tsc3@mit.edu


Conference LogoTESS Science Conference III

July 29 - August 2, 2024, MIT / Cambridge, USA

Talks

Presenters should upload all their presentation files here. Note that presentation files should be in PPT, Keynote, or PDF format. Speakers are required to upload all presentation files at the latest, during the coffee break before their talk.

We would like to record all talks and make the recordings publicly available. If you agree to your talk being recorded and made public please sign this speaker release form form and send it to tsc3@mit.edu. If you wish your talk to not be recorded please inform the LOC by sending a message to tsc3@mit.edu.

The screen used for presentations is optimized for a 16:9 aspect ratio.

Optionally, speakers can upload their presentations to Zenodo (see below) in order to make them public.

Talk Design

Below are some tips on how to prepare and give inspiring scientific conference talks. This selection is only meant to give a short overview and inspiration, and is by no means a complete list. The TESS Science Conference neither recommends nor discourages any ideas.

Posters

General

The poster size is limited to 45 inch (114.30 cm) wide and 44 inch (111.76 cm) high. Posters can be put up starting 8:30am Monday morning, July 29, and should be taken off by 3:30pm on Friday, August 2, which is the end of the afternoon coffee break.

Poster Design

Below are a few examples and tutorials on how to create inspiring scientific posters; some in a more traditional format, others showing creative alternatives. This selection is only meant to give a short overview and inspiration, and is by no means a complete list. These designs are purely for inspiration, the TESS Science Conference neither recommends nor discourages any poster design ideas.

Printing your poster in Cambridge, MA

There are two options near the conference to print your poster: MIT Copytech and Fedex.

FedEx

One option to print your poster is the FedEx Office close to the campus at 600 Technology Square, Cambridge, MA 02139. More information can be found here: FedEx Office. You can also e-mail your poster to usa0992@fedex.com and call their office at (617) 494-5905 to confirm your order.

MIT Copytech

If you like to print your poster on campus, MIT has a print center called Copytech. The prices and different printing options can be found here: MIT Copytech

Non-MIT attendees should email copytech@mit.edu with their poster file and printing instructions. Payment will be collected over the phone (credit card, no amex) and then the order will get into production.

MIT attendees can upload their poster electronically through MIT Copytech and pay via credit card or mit cost object.

The MIT Copytech is located on the main campus in Building 11-004, 77 Massachusetts Ave, Cambridge, MA 02139: MIT Copytech Location & Hours. They can be reached over the phone on +1 (617) 253-2806.

Note that the print center is NOT open on weekends and the opening hours are 08:00 - 17:00 EDT Monday - Friday.

Please make sure that you submit the order at least 5 business days before the conference. Submitting your poster as a PDF will ensure highest quality, although PNG and JPEG are also supported.

You can either pick up the poster yourself at MIT Copytech (discuss the pick-up plan in your email), or you can add a note that your poster is part of the TESS Science Conference and that the conference organizers will do the pickup. One of the LOC members will then pick up all the posters and bring them to the conference location (for this, your poster will have to be printed by Thursday, July 25). If your poster is printed afterwards, you will have to pick it up yourself.

Zenodo

Posters will be made freely available online through Zenodo, an EU funded data and project repository. All submissions must therefore be made on Zenodo's webpage.

To facilitate accessibility and visibility, all contributions to the proceedings will be indexed on the ADS.

Briefly, all submissions are assigned a Digital Object Identifier (DOI) number by Zenodo, making contributions citable. Once all contributions are received, ADS will be notified, they will scrape the Zenodo collection, and then ADS will index each of the contributions as part of a larger volume (Proceedings for TESS Science Conference III).

Instructions for uploading your poster on Zenodo will follow later.

How to submit your contribution

Submitting to Zenodo is rather simple, but it's important that all metadata be properly included so that articles get properly indexed on ADS. Below is a series of screenshots taking you through the submission process from start to finish.

Step 01: Follow the link to the submission page for TESS Science Conference III.

Step 02: You'll be presented with a login screen:



If you have a Zenodo account, proceed to login. If you do not, you may login using your ORCID, GitHub or OpenAIRE account, or you may create a new account using the "Sign Up" button located at the bottom of the frame.

Step 03: Once you login, you'll be presented with an "Upload" screen. Make sure that the “TESS Science Conference III @ MIT, 2024” community is selected in the top part of the webpage (red rectangle in the screenshot underneath). If you do not see this, start typing it into the search bar after clicking “change” and it will automatically pop up.



Click the button to choose a file on your local machine, or drag and drop a file directly onto the screen.

Step 04: After you select one or more files where you can start to fill out a wide variety of file metadata on the boxes below the upload box. We will come back to the section on the right side of the upload box (“Draft” and “Visibility”) at the end.

First, select whether you already have a Digital Object Identifier for your upload (DOI). Select “No”, unless you know for a fact that the document you're upload already has an assigned DOI. If you are unsure, then it likely does not already have a DOI.



Step 05: Now, start filling out information about your document.



First, select the type of file you have just uploaded:

  • Poster: Select "poster" if you are presenting a poster at the conference. In this case the uploaded file should be a PDF of your poster.
  • Presentation: Select “presentation” if you are presenting a contributed talk at the conference. In this case, the uploaded file can be the PDF of your slides.
Enter the title of your article/poster/talk. Enter today's date for the publication date, if it's not automatically done for you.

Enter the name of each author and their affiliation by clicking “Add creator” under Creators.

NOTE: The names and affiliation are required. Names should be formatted as "Last Name, First Name". ORCID is optional.



Lastly, enter the description of your submission. This should be your submitted abstract.

You will be asked to fix this if you do not do it correctly the first time. It's important for ADS that this be done properly. Continue to fill in the requested information, including the Description (i.e., Abstract).

Step 06: Choose access rights and a license for your work. You are strongly encouraged to select Open Access and a permissive license so that people can easily access your work.



Step 07: Fill out the “Recommended information section”.



Contributors: Add "Audenaert, Jeroen" as an editor. Note, family name: “Audenaert” and Given name: “Jeroen”. Select Editor from the dropdown menu.

Fill in keywords. You can have as many keywords as you like, but the first keyword should be one from the following list because we will sort posters by the value in the first keyword. Any poster that does not match one of the major science topics below will be listed as "other".

  • Solar System
  • Exoplanets
  • Stellar Astrophysics
  • Galactic Astrophysics
  • Extragalactic Astrophysics
  • Data Analysis Techniques
  • TESS synergies with space missions and Surveys


Step 08: Optionally, you can enter the following information:

Optionally, you may specify funding information.

If you submitted to the arXiv and/or your article was already indexed to ADS, add the related identifying information so that Zenodo and ADS will link all of the contributions into one neat little package.

Step 9: Given credit where credit is due! If you referenced various works in your article, talk, or poster, give them credit by adding the reference information (yes, citations will be counted on ADS, but ADS will only know about them if you enter the information in the "References" section). See the image below about how to format the references:



This is basically a copy-paste of a bibliography.

Step 10: Publishing information: leave this section empty.

Step 11: Fill out information about the Workshop as shown below:



  • Title: TESS Science Conference 3
  • Acronym: TSC3
  • Place: Massachusetts Institute of Technology, Cambridge, MA, USA
  • Dates: July 29 - August 2, 2024
  • Website: https://tsc.mit.edu/

Step 11: Review the information to make sure you've done everything properly and then click "Submit for review" on the right side of your screen! Or, if you'd like to save it and publish later, click "Save"

Step DONE: Congratulate yourself on a job well done.

Full Poster List

Poster ID Name Affiliation Poster Title Abstract
1.01 vasuda trehan university at albany, SUNY Exoplanet Habitability: A Multifactorial Approach (Using AI to study and predict planet habitablity) As space technology advances, the possibility of humans becoming an interplanetary species becomes more realistic. Companies like SpaceX and Blue Origin are working towards making space travel extended distance and more accessible to people. With the help of space observatories like James Webb and Hubble telescope, we can now study exoplanets and gather data about them. An AI model can be developed based on this collected data, that can be used to predict the conditions of habitability of these exoplanets. Models training and development can use techniques like Bayesian data analysis to predict the spectral features of extrasolar planets, which is a challenging task that involves forecasting spectral bin heights with multi-planetary parameters. Another approach can be using Monte-Carlo simulation, by randomly sampling values from the specified distributions for each parameter collected for the exoplanet. Perform calculations or simulations that determine habitability based on these parameter values. A comparison of these various models and many more ultimately will help us to understand the habitability of exoplanets better. Hence studying the destination before planning and developing human society on exoplanets.
1.02 Romy Rodriguez Harvard TOI-4994b: An Eccentric Sub-Saturn on a 21 day Period Orbit around a Solar Analog We present the discovery and characterization of a new transiting Saturn-mass planet on a 22-day orbit around a Sunlike star discovered by TESS. We confirm the planetary nature of this object with high-resolution radial velocity observations from CHIRON and the Planet Finder Spectrograph (PFS). We perform a global fit of the system to determine the physical properties of the star and planet and find a preliminary eccentricity of e = 0.25, which makes this planet a potentially interesting target for studies of high-eccentricity migration as well as for follow-up atmospheric observations with JWST.
1.03 Jaeyi Song Harvard-Smithsonian Center for Astrophysics Increased Precision in Stellar Parameters of HD189733b and HD209458 Using TESS Light Curves HD189733b and HD209457 are both canonical exoplanets with deep transits, short periods and bright host stars, allowing us to determine a precise and accurate radius and temperature. We used EXOFASTv2 to run a series of stellar fits and were able to infer HD189733b’s radius to 1.1% (0.7585: +0.0088, −0.0086 R⊙) and its temperature to 1.2% (5141: +61, −60 K) - a factor of 2 improvement in precision over previous studies. Our stellar radius is 2.6 sigma discrepant from its CHARA-measured interferometric value (0.805: +0.016, −0.016 R⊙) which, we argue, are due to systematic errors in the interferometric radius. HD189733’s angular size is only 1.1 mas, and interferometric radius measurements have shown significant disagreements when the angular diameter is below 1.25 mas. For HD209458, we were able to measure the radius to 1.5% (1.169: +0.017, −0.018, R⊙) and the temperature to 1.8% (6150: +120, −100 K) - a factor of 2.8 improvement in precision over alternative studies. In this paper, we generalize our procedure so we can accurately and precisely determine the radii and temperatures of stars with high signal to noise transiting planets while carefully accounting for systematic errors.
1.04 Pa Chia Thao UNC Chapel Hill The Discovery of a Two-Planet System in the 200 Myr MELANGE-5 Association Young (<500 Myr) planets are critical to studying how planets form and evolve. Among these young planetary systems, multi-planet configurations are particularly useful as they provide a means to control for variables within a system. Here, we report the discovery and characterization of a young planetary system, TOI-1224. We show that the planet-host resides within a young population we denote as MELANGE-5. By employing a range of age-dating methods -- isochrone fitting, lithium abundance analysis, gyrochronology, and Gaia excess variability -- we estimate the age of MELANGE to be ~200 Myr. In addition to a planet candidate detected by the TESS pipeline and alerted as a TESS Object of Interest, TOI-1224 b, we identify a second planet, TOI-1224 c, using custom search tools optimized for young stars. We find the planets are ~2 and 3 R⊕ and orbit their host star every 4.18 and 17.95 days, respectively. With their bright (K=9.1 mag), small (R*=0.44R☉), and cool (Teff=3326 K) host star, these planets represent excellent candidates for atmospheric characterization with JWST.
1.05 Huan-Yu Teng Korea Astronomy and Space Science Institute The ~50-Myr-Old TOI-942c is Likely on an Aligned, Coplanar Orbit and Losing Mass We report the observation of the transiting planet TOI-942c, a Neptunian planet orbiting a young K-type star approximately 50 Myr years old. Using Keck/HIRES, we observed a partial transit of the planet and detected an associated radial velocity anomaly. By modeling the Rossiter-McLaughlin (RM) effect, we derived a sky-projected obliquity of |lambda|=24+/-14 degrees, indicating TOI-942c is in a prograde and likely aligned orbit. Upon incorporation of the star's inclination and the planet's orbital inclination, we determined a true obliquity for TOI-942c of psi< 43 degrees at 84% confidence, while dynamic analysis strongly suggests TOI-942c is aligned with stellar spin and coplanar with the inner planet. Furthermore, TOI-942c is also a suitable target for studying atmospheric loss of young Neptunian planets that are likely still contracting from the heat of formation. We observed a blueshifted excess absorption in the H-alpha line at 6564.7 Ang., potentially indicating atmospheric loss due to photoevaporation. However, due to the lack of pre-ingress data, additional observations are needed to confirm this measurement.
1.06 Alicia Kendall University of Leicester 1 Neptune, 2 Saturns: 3 Giants under 700K For orbital periods longer than 10 days, there is a dearth of well-characterized transiting gas giants, where they become valuable probes of planet formation and evolution. We present three of these planets with orbital periods solved through ground-based follow-up efforts by the NGTS Long Period Planets Programme, each initially identified as single transit events in TESS Sectors. With an orbital period of 43.1 days, TIC-147277741b is one of the longest period well-characterized transiting Neptunes. Orbiting a star that is bright in K band (≃7.9 mag) and with a TSM of 31, it is both amenable and interesting for spectroscopic follow-up with instruments such as MIRI or ARIEL. TOI-4940b and TOI-6669b are warm Saturns on ≃25 day orbits, the latter having moderate eccentricity (e ≃ 0.2). Each has an equilibrium temperature <700K, with TOI-6669b especially cold at ≃460K. It maintains a TSM of 46, high for a cool near-Jupiter sized planet, rendering it a promising candidate for cool atmosphere studies.
1.07 Avi Shporer MIT GJ 238 b: A Mars-size planet orbiting an M2.5 dwarf star at 15.2 pc The search for small terrestrial planets, the size of Earth and smaller, is now at the forefront of exoplanet research. Their discovery puts the Solar System terrestrial planets in the context of exoplanets. We report the discovery of GJ 238 b, a transiting planet close to Mars radius (0.566 ± 0.014 Earth radius, or 1.064 ± 0.026 Mars radius), at an orbital period of 1.74 day. The transit signal was detected by the TESS mission and designated TOI-486.01. The star's position close to the Southern ecliptic pole allows for almost continuous observations by TESS when it is observing the Southern sky. The host star is an M2.5 dwarf with V=11.57 ± 0.02 mag, K=7.030 ± 0.023 mag, a distance of 15.2156 ± 0.0030 pc, a mass of 0.42 Solar, a radius of 0.43 Solar, and an effective temperature of 3,485 ± 140 K. We validate the planet candidate by ruling out each of the false positive scenarios, based on archival data and ground-based follow-up observations. Validation was facilitated by the host star's small size and high proper motion of 892.633 ± 0.025 mas per year.
1.08 Kimberly Armas Harvard University A sub-Neptune planet at the edge of the hot Neptune desert and a possible planetary companion orbiting the G-type star TOI-1943 We report the physical characteristics of the sub-Neptune TOI-1943b and the presence of an additional planetary companion orbiting the Sun-like and relatively bright (V=10.6, K=9.0) star TOI-1943. Using the EXOFASTv2 software package to model TESS light curves and PFS+HARPS radial velocity data (RVs), the sub-Neptune is determined to have a radius of $R_{p} = 3.21^{+0.18}_{-0.17}R_{\oplus}$ and an orbital period of $1.74^{+,0.0000032}_{-0.0000035}$ days. Fifty spectra obtained from the PFS and HARPS spectrographs verify the status of this planet since the radial velocities appear to vary in phase with the photometric ephemeris. We can estimate that the planet has a mass of $17.0^{+1.3}_{-1.2} M_{\oplus}$, a median density of $2.82^{+0.55}_{-0.47} \ \text{g/cm}^{3}$ which is nearly twice the density of Neptune, and a relatively high equilibrium temperature of $1587^{+58}_{-48}$ K. The PFS and HARPS RVs also reveal a periodic signal on a longer timescale of $46.05^{+0.47}_{-0.22}$ days that may be caused by another planet. Given the high equilibrium temperature and density of TOI-1943b and its stellar host's brightness, it is amenable to future JWST observations to measure its atmospheric composition.
1.09 Katharine Hesse MIT TOI-4189 and Contributions to the Broader Sample of TESS Sub-Neptunes TESS has supplemented the findings of previous transit missions like Kepler, particularly contributing to the existing population of sub-Neptunes. Kepler found over 2400 sub-Neptunes but most were around fainter stars, with less than 5% having precise RV mass measurements to date. TESS has confirmed over 200 sub-Neptunes, with nearly half having precise RV masses. As the mission continues, this sample of sub-Neptunes around bright stars continues to grow, enabling mass and orbit measurements to further answer questions surrounding sub-Neptunes. Particularly, TESS is finding longer period sub-Neptunes such as the TOI-4189 system, consisting of a bright (Vmag~9.36) sun-like star with an inner non-transiting sub-Neptune (9.9 days) and an outer transiting sub-Neptune (46.9 days). Filling in the sub-Neptune parameter space with such systems will allow better understanding of the composition, formation, and evolution of these planets. We will discuss the new sub-Neptunes found by TESS, particularly the case of TOI-4189, and shared characteristics such as mass, density, and eccentricity of the existing TESS sample.
1.10 Stephen Kane University of California, Riverside Unveiling the dynamical origin of the eccentric transiting planet HD17156b HD 17156b was one of the first known transiting planets, and is particularly notable because it was the first transiting planet to diverge from hot-Jupiter discoveries. The planet occupies a 21.2 day eccentric (e = 0.68) orbit, offering important insights into the evolution of planets in extreme orbits. We present Transiting Exoplanet Survey Satellite photometry that cover five transits of the planet, and combine these data with radial velocities and speckle imaging that show the system does not harbor any additional giant planets interior to 10 AU, nor does it contain stellar companions. The lack of companions and the age of the system indicate that the eccentricity of the known planet likely resulted from a previous planet-planet scattering event. Our dynamical simulations reveal an original architecture that includes an additional planet that was ejected from the system, leaving behind a legacy of the currently observed high eccentricity for HD 17156b.
1.11 Jingwen Zhang Institute for Astronomy, University of Hawaii A Testbed for Tidal Migration: the 3D Architecture of an Eccentric Hot Jupiter HD 118203 b Accompanied by a Misaligned Outer Giant Planet In the talk, I will present the discovery of a long-period giant planet HD 118203 c (mc~8.4MJ, a~5.5AU) exterior to a close-in eccentric hot Jupiter (Pb~6.135 days, mb~2.14Mj, eb~0.31). Using Rossiter-Maclaughlin observations from the Keck Planet Finder, we measure a low sky-projected obliquity of around -11 deg for HD 118203 b and detect p-mode oscillations in the host star, confirming its evolved status. Combined with the stellar rotation period from TESS, we constrain the true obliquity of HD 118203 b as ~17 deg, indicating the tidal forces from the host star have realigned the orbits of the hot Jupiter. Furthermore, we constrain the mutual inclination between the hot Jupiter and the outer planet to be at least 40 deg (1 sigma significance) by combining long-term radial velocities and Hipparcos-Gaia astrometric acceleration. We also constrain the stellar obliquity for HD 118203 c to be 43 deg(1 sigma significance). The hierarchical star-planet-planet architecture of the HD 118203 system supports the high-eccentricity tidal migration hypothesis. The observed mutual inclination between two planets implies the system may have experienced Kozai-Lidov oscillations or planet-planet scattering events historically.
1.12 Victoria DiTomasso Center for Astrophysics | Harvard & Smithsonian The Lone Transit: Characterizing a Long-Period Neptune-Sized Exoplanet, HD60779b The TESS mission is inherently limited in its ability to discover planets with orbital periods >25 days. Characterizing longer period exoplanets, however, is essential for bridging the gap between our knowledge of planets and their formation gained from Solar System planets and from the shorter period, hotter exoplanets that have been primarily studied thus far. We present an analysis of a 3 REarth single TESS transit candidate around a nearby, sunlike star, HD60779. Using HARPS-N, we obtained 270 RV measurements over 2.5 years and, after exploring a variety of stellar activity mitigation techniques, find the data are best explained by a stellar activity model combined with two Keplerian models. We constrain the orbital period and mass of the transiting planet to Porb=30d, M=13.1+/-1.3 MEarth – making this a warmer, denser Uranus-mass planet. Using this fit, we can predict future transits with sufficient accuracy to allow for the detection of a second transit, which would then provide the necessary precision to schedule JWST observations. We also constrain the additional planet to Porb=104-106d, M sin i=27+/-2.5. Together, these planets will serve as a multi-planet system whose members have masses constrained to 10% precision.
1.13 Isobel Shefali Lockley University of Warwick TOI-1117: three Sub-Neptunes, one in the Neptunian Desert I present the discovery of three Sub-Neptunes around the Sun-like star, TOI-1117. Performing a joint fit of TESS light curves and HARPS radial velocity data revealed an inner transiting planet, TOI-1117b, and two non-transiting planets, TOI-1117c and TOI-1117d. TOI-1117b lies within the orbital period parameter space known as the ‘Neptunian desert', where only a small fraction of exoplanets have been found. It is also situated in the ‘radius valley’, where planets are rare due to photoevaporation. To investigate this, we derived the internal structure of TOI-1117b and compared it with simulations, finding an envelope mass fraction of <1% but a density lower than Earth’s. This could be explained by the presence of water. Furthermore, all three planets were found to have short periods, 2.228, 4.579, and 8.67days, in a near 4:2:1 resonance chain. I present results of resonance analysis and stability analysis, showing eccentric orbits to be highly unlikely and limiting plausible inclinations. This implies steady and stable migration, contradicting high-eccentricity migration theories.
1.14 Yoshi Nike Emilia Eschen University of Warwick 9 new M Dwarf Planet Candidates from TESS Including 5 Gas Giants M dwarfs are the most abundant stellar population in the milky way, making up around 70% of all stars. Since these low-mass stars are also smaller and cooler, their habitable zones lie at much smaller orbital distances compared to sun-like stars, and their higher planet-to-star radius ratios are favourable for exoplanet exploration. We present the detection of 9 new planet candidates orbiting M dwarfs, identified using an independent search and vetting pipeline applied to TESS Full-Frame Image (FFI) data from Sectors 1 to 63. Our candidates include planets as small as 1.4 Re, with orbital periods up to 20 days. Among the 9 new candidates, we identified 5 gas giants, which represent a rare and unexpected outcome of planet formation. Our findings add to the growing sample of giant planets around M dwarfs found by TESS. We discuss their follow-up potential for mass measurements through radial velocity observations and atmospheric characterisation through transmission spectroscopy. We highlight TIC 12999193.01 as a particularly unique gas giant candidate in an eccentric orbit and excellent potential for atmospheric characterisation.
1.15 Ismael Mireles University of New Mexico Three new planets in two dynamically excited TESS warm Jupiter systems We present the discovery of three new planets in known warm Jupiter systems. TOI-1670 d is a sub-Neptune on a 123 d orbit exterior to the sub-Neptune TOI-1670 b and warm Jupiter TOI-1670 c. It lies close to a 3:1 resonance with the well-aligned TOI-1670 c and exhibits transit timing variations (TTVs) of over an hour. TOI-201 c is a super-Earth on a 5 d orbit interior to the warm Jupiter TOI-201 b, while TOI-201 d is a Jovian planet exterior to both that transited only once in TESS observations and has an orbital period over 250 d. The transit of TOI-201 d coincides with sudden TTVs for TOI-201 b, indicating TOI-201 d is eccentric and a rare type of warm Jupiter companion. We constrain the mass and orbit of TOI 201 d using TESS photometry, transit timing variations, and archival and new radial velocities. We validate TOI-1670 d and TOI-201 c using TESS photometry and archival observations. Both warm Jupiter systems are dynamically active and consist of 3 planets around an F star, but their specific properties highlight the different evolutionary paths warm Jupiter systems can follow. These systems also highlight how the TESS extended missions can detect smaller and longer-period planets, including around known planet-hosting stars.
1.16 Emily Gilbert NASA JPL Radial Velocity Observations Reveal a Rocky Composition of the Earth-sized Habitable-Zone Planet, TOI 700 d The TOI-700 system is one of the most exciting TESS discoveries to date. It is a four planet system with two terrestrial planets in the star’s Habitable Zone (TOI-700 e and d). Recent work has given much attention to M dwarf stars as planet hosts, as their small sizes make it easier to detect and characterize planets. However, M dwarfs, especially those with the lowest masses, exhibit more intense and longer lasting magnetic phenomena than Sun-like stars, emitting frequent flares which may erode planet atmospheres over time. TOI-700 is an ideal system for further characterization of its planets. We report on radial velocity observations with ESPRESSO on the VLT to further characterize these worlds. 164 RV data points show that TOI-700 c (2.6 R_earth) is a low density sub-Neptune (K = 1.08 m/s, M = 2.4 M_earth, rho = .7 g/cc). TOI-700 d (1.16 R_earth) is an iron-rich terrestrial world (K = .72 m/s, M = 2.1 M_earth, rho = 7 g/cc). We will discuss the implications these measurements have on the ability for the HZ planets to maintain their atmospheres.
1.17 Zahra Essack The University of New Mexico Singling Out a Super-Jupiter: Confirmation of a Long-Period Giant Planet Discovered with a Single TESS Transit We report the discovery and confirmation of TOI-4465 b, a 1.2 RJup, 6.1 MJup giant planet orbiting a G dwarf star. The planet was detected as a single-transit event in TESS Sector 40. Radial velocity (RV) observations of TOI-4465 using the Automated Planet Finder telescope show a planetary signal with an orbital period of ~102 days, and an orbital eccentricity of e=0.24. TESS re-observed TOI-4465 in Sector 53, and will again in Sector 80, but will not detect another transit of TOI-4465 b. A global ground-based photometry campaign was initiated to observe another transit of TOI-4465 b after the RV period determination. The ~12 hour-long transit event was captured from 17 sites around the world, and included observations from several citizen scientists. TOI-4465 b is a dense (4.3 g/cm3), warm giant planet. We use giant planet structure models to estimate its bulk heavy-element content, and find that TOI-4465 b is enriched in metals at a level consistent with the core accretion theory of giant planet formation. Increasing the number of long-period planets by confirming single-transit events is crucial for understanding the frequency and demographics of planet populations in the outer regions of planetary systems.
1.18 Amy Tuson UMBC / NASA Goddard Uncovering Long-Period Transiting Exoplanets with TESS and CHEOPS Long-period transiting exoplanets are incredibly important, allowing us to study planets with temperatures similar to those in our own solar system. However, due to its observing strategy, TESS is heavily biased towards the discovery of short-period planets. I am combining TESS observations with CHEOPS follow-up to increase the yield of long-period planets. I created a specialised pipeline to discover TESS "duotransits". These are the observational signatures of long-period planets, characterised by two transits separated by a large gap, but their exact orbital periods are ambiguous. My pipeline discovered five new duotransits that were then observed by the CHEOPS Duotransit Program to reveal their true periods. I will present my pipeline, its discoveries and the sample of small, long-period planets being uncovered by TESS and CHEOPS, including the Neptune-mass planet TOI-5678 b and the bright multi-planet system HD 15906.
1.19 Akihiko Fukui The University of Tokyo Discovery of an Exo-Venus Transiting an Inactive M dwarf at 12 pc Despite hundreds of discoveries of terrestrial-sized planets, the number of those with low equilibrium temperatures and minimal XUV irradiation - conditions conducive to retaining a thick atmosphere - remains limited, in particular those that are amenable to atmospheric observations. We present the discovery of an Earth-sized planet transiting Gliese 12 (TOI-6251), an M dwarf located 12 pc away (Kuzuhara, Fukui, et al. in press). The planetary candidate, TOI-6251.01, was initially identified by SPOC with an ambiguous orbital period of either 25.7 d or 12.8 d. Follow-up observations using the MuSCAT series confirmed the true transit period to be 12.8 d and, combined with TESS photometric data, measured the planetary radius to be 0.96 Earth radii. High-resolution imaging with Gemini/NIRI and Keck/NIRC2, as well as radial-velocity measurements from Subaru/IRD and CARMENES, validated the planetary nature. X-ray data from XMM-Newton revealed that the host star is inactive. With an equilibrium temperature of 315 K and a transmission spectroscopy metric of 17 - comparable to those of the TRAPPIST-1 planets - Gliese 12b represents a promising terrestrial-sized, temperate planet that is suitable for atmospheric characterization with JWST.
1.20 Kai Ikuta The University of Tokyo Discovery of a short-period sub-Neptune and an outer planetary companion around a mid M-dwarf We present the discovery of two multiplanetary systems with a transiting short-period sub-Neptune and a non-transiting outer planetary companion around an M-dwarf with an effective temperature of 3450 K (Ikuta et al., in preparation). The transiting planets with orbital periods of 1.53 and 1.54 days were identified by the TESS and followed up by ground-based telescopes with the Multicolor Simultaneous Camera (MuSCAT) series. The planetary masses were measured by the intensive observations with the InfraRed Doppler instrument (IRD) on the Subaru telescope. The analysis reveals that the transiting planets have radii of 2.0 and 2.4 $R_{\rm earth}$ and masses of 6 and 8 $M_{\rm earth}$. It is also suggested that outer planetary companions have orbital periods of 141 and 29 days and masses of $\sim$ 65 and 14 $M_{\rm earth}$ through the long-term monitoring of the radial velocity with the Subaru/IRD. In the context of the water-world scenario as a third population in the radius valley for M-dwarfs, these transiting planets would have mass densities to compose of rocky cores with comparable amounts of water. The outer planetary companions also provide clues to the composition of the transiting planets and their formation processes.
1.21 Anne Dattilo UC Santa Cruz TOI-6109: Two Young sub-Neptunes confirmed by CHEOPS and TESS Young planets with mass measurements help differentiate atmospheric mass-loss processes, but these systems are rare and the masses are difficult to measure due to stellar activity. We report the discovery of a planetary system around TOI-6109, a young, approximately 80Myr-old Sun-like star in the Alpha Persei cluster. It hosts at least two transiting Neptune-like planets and up to two additional planet candidates within 15-day orbital periods. Using 30 CHEOPS orbits and photometric follow-up observations from the ground, we confirm the signals of the two innermost planets. TOI-6109.01 has an orbital period of P=8.528 days and a radius of R=4.87 Re. The interior planet, TOI-6109.02, has an orbital period of P=5.695 days and a radius of R=4.21 Re. These planets orbit just outside a 3:2 mean motion resonance. The TESS lightcurve also shows evidence of two additional signals that could be planets, also at mean-motion resonance. The near-resonant configuration presents the opportunity to measure the planet's mass via TTV measurements and to bypass difficult RV measurements. If we can measure the mass of the planets in the TOI-6109 systems, we will be able to test theoretical models of atmospheric mass loss.
1.22 Benjamin Davies University of Warwick Finding Circumbinary Planets: A Transit Detection Framework for TESS Eclipsing Binaries The detection of the first circumbinary planet (CBP) was an exciting breakthrough in exoplanetary science, but the number of known CBPs remains small. Only 14 transiting CBPs have been discovered, making the study of their formation, evolution, and bulk properties difficult. Here, I present a framework for detecting transiting CBP candidates from TESS light curves of eclipsing binaries. I outline how the data is processed, including masking eclipses and detrending, as well as the procedure for detecting individual candidate transit events. In conclusion, I consider how potential candidates can be vetted and discuss follow-up observations necessary for their confirmation.
1.23 Dominic Oddo University of New Mexico Towards Transiting Tatooines: A search for circumbinary planets with TESS Circumbinary planets (CBPs), those orbiting outside tight stellar binaries, present a compelling intersection between binary systems and planet formation. Despite their significance, the limited sample size of detected CBPs leaves numerous population-level questions unanswered. Our research addresses this gap by conducting a comprehensive search for transiting CBPs within the light curves of eclipsing binaries (EBs) observed by the NASA Transiting Exoplanet Survey Satellite (TESS) mission. We employ methods for masking EB signatures and identifying transit events. Specifically, we focus on the challenging task of detecting transiting CBPs orbiting tight binaries comprised of two M dwarfs (M+Ms), a scenario with profound implications for our understanding of planet formation in such systems. Preliminary findings from our search efforts are discussed, shedding light on the progress made and the potential impact of our research. Furthermore, we outline future steps towards validating candidate CBP detections, emphasizing the ongoing nature of our investigation and its contribution to advancing our understanding of circumbinary planetary systems.
1.24 Karen Collins SAO/CfA Understanding ExoFOP and TFOP TOI Dispositions to Maximize the Science from Your Exoplanet Program ExoFOP-TESS provides two planet candidate dispositions, TESS Disposition and TFOPWG Disposition, for each TOI. Additionally, TFOP maintains various detailed dispositions for each TOI. The dispositions on ExoFOP are restricted to only a few high-level disposition codes while the TFOP dispositions have tens of possible codes. Understanding how the various disposition codes are curated and how they flow through the various systems to produce the ExoFOP dispositions can help increase the productivity of your telescope time and maximize the science from your exoplanet program. We will describe these processes, explain how the detailed dispositions map to high level ExoFOP dispositions, point to critical sources of information on ExoFOP and other TFOP web-based tools, and explain the resources available to help make the best use of data uploaded to ExoFOP.
1.25 Brian Jackson Boise State University Citizen Science in the Central Idaho Dark Sky Reserve The Central Idaho Dark Sky Reserve is the USA's first gold-tier certified dark sky reserve. To support outreach and education in the Reserve, NASA’s Science Activation funded the Central Idaho Dark Sky Reserve STEM Network based at Boise State. This grant has provided funds to purchase fifty eQuinox 2 telescopes to distribute among public educators throughout the Reserve. The scopes have motorized mounts, an imaging system, and an aperture 114 mm in diameter. They are also automated and designed specifically for citizen science, including an observing mode for collecting exoplanet transits, with an online data repository. The imaging system also involves a Bayer filter to generate blue, green, and red images spanning from 400 to 1000 nm in wavelength. Demosaicking frames collected during a transit can produce color-resolved transits. For planetary candidates discovered by TESS, such transits have been shown to help distinguish blended eclipsing binaries from true planetary systems since binary eclipses can be wavelength-dependent and planetary transits are not. In this presentation, we will discuss prospects for such a program of citizen science using eQuinox 2 scopes and will present preliminary observational results.
1.26 Francis P. Wilkin Union College Union College Contributions to Exoplanet Science through the TESS Follow-up Observing Program (TFOP) We describe the contributions to TFOP by students and faculty at Union College, a small, liberal arts school that operates a 20" reflecting telescope and CCD camera. Since joining the TFOP Science Group 1 (SG1) in June 2019, eight undergraduate students and their faculty advisor have analyzed ~77 exoplanet planet candidates using observations from the Union College Observatory and remote telescopes operated by Las Cumbres Observatory (LCO), iTelescope.net, and Telescope.Live. Additionally, students of the Observational Astronomy course AST 230 have contributed their analyses of observations to SG1 as class projects and presented their results at local conferences.
1.27 Avi Shporer MIT LCO Key Project: LCO follow up of TESS transiting planet candidates Identifying the real planets among the many TESS planet candidates throughout the entire sky requires follow-up observations. An efficient follow-up requires (1) a global facility and (2) a large amount of telescope time. Our Las Cumbres Observatory (LCO) Key Project is designed to do just that, with about 2,600 hours of telescope time per semester for 6 semesters, 2023B - 2026A. This Key Project follows a previous similar 3-year Key Project, from 2020B - 2023A. LCO telescopes are fully automated, including 10 x 0.4m, 11 x 1.0m, and 2 x 2.0m telescopes in 7 sites worldwide. We are using all LCO telescopes, all equipped with imagers, and we have time also on the high resolution NRES spectrographs, installed on 1.0m telescopes in 4 sites. Imagers are used to observe the TESS candidates during predicted transit time and check if the transit signal seen in TESS data originates from the target or from a nearby star blended with the target in the TESS wide PSF. The NRES spectrograph is used for measuring the stellar parameters of bright host stars down to 10th magnitude, identifying FPs (SB1, SB2), and measuring the orbits of massive planets. This Key Project, along with the previous one, are part of most TESS planet discoveries.
1.28 Owen Mitchem University of Oregon TESS Follow-up at the Pine Mountain Observatory: Undergraduate Research at Small and Mid-Sized Facilities The University of Oregon’s Pine Mountain Observatory (PMO) is a mid-sized, research-grade facility nestled in the heart of Central Oregon. Throughout our tenure as members of the TESS Follow-up Observing Program (TFOP), our team of undergraduate researchers has transformed a small telescope at a mid-sized observatory into an instrument capable of making significant contributions to the TFOP mission. The resurgence in demand for time at facilities like PMO, spurred by recent large survey missions such as TESS, has revitalized the opportunities for research to be conducted at our facility. Utilizing refinements made to our observational procedures as members of the TFOP, our team has made high signal-to-noise detections of 12 transiting Hot Jupiters with events ≳5 ppt around host stars with brightnesses in the range of mV 7-15. Leveraging the newly developed remote observing capabilities of our 0.35m telescope, we anticipate continuing this work into the 2024 observing season, implementing a high cadence of precise TFOP observations. With an increase in research activity and a desire for further collaboration within the exoplanet science community, we seek to broaden the impact of the undergraduate research being conducted at PMO.
1.29 Rob Wittenmyer University of Southern Queensland Minerva-Australis: the next five years of a TESS follow-up machine Minerva-Australis is an array of four 0.7m telescopes in Queensland, Australia that has been wholly dedicated to radial-velocity follow-up of TESS planet candidates for nearly six years. It has contributed data to the confirmation of 40 TESS planets, about 10% of all confirmed TOIs. I give an update on the performance of the observatory, with recent upgrades including the addition of a fifth 0.8m telescope and precision multi-telescope photometric capability. I also describe future science plans beyond mass measurements of TESS planets: 1) expanded wavelength coverage to include activity indicators, 2) photometric ephemeris refinement for small planets, 3) long-term RV monitoring for outer giant companions in TESS systems, and 4) preparatory science for Habitable Worlds Observatory target stars to fully understand the presence or limits on their planetary systems.
1.30 Sakhee Bhure University of Southern Queensland Precision Photometric Follow-up of High-value Southern Hemisphere TESS Targets with MINERVA-Australis The MINERVA-Australis facility, a southern-hemisphere robotic telescope array with instruments capable of providing both precision radial velocity spectroscopy and transit photometry for TESS follow-up. Its newly incorporated ability to perform simultaneous photometry of one target with four separate telescopes effectively samples entirely independent atmospheric cells for a fourfold reduction in scintillation. This upgrade provides a combined photometric precision comparable to large ground-based telescopes as demonstrated by the recent detection of a 1.0 R_Earth planet. We present a demonstration of the array’s sensitivity and plans to follow-up ~75 of these high-value TESS candidates in order to obtain precise transit times and perform transit light-curve analyses. By working towards the TFOP SG1 goals of identifying false positives and transit timing variations, and refining ephemerides, MINERVA-Australis would be able to recover the signals of planets most amenable for further follow-up by JWST and the ELTs.
1.31 Khalid Barkaoui University of Liège Earth to sub-Neptune-like planets around M dwarfs stars M dwarf stars are the most common stars in our galaxy, which have effective temperatures of <3800K. M-dwarfs are excellent targets to search for transiting Earth- to sub-Neptune-like planets. Due to their low masses, small sizes and low luminosities, these systems provide a unique opportunity to investigate the physical properties and chemical composition of the planets, and make a link to their formation, evolution and interior structure, as well as to derive the slope of the radius valley. Moreover, these systems are prime targets for detailed atmospheric characterization through emission and transmission spectroscopy with JWST space telescope. In this talk, I will describe our observing strategy making use of the full SPECULOOS network. I will also present exciting results of the survey.
1.32 Alicia Kendall University of Leicester Identifying transiting Neptunes and sub-Neptunes in the NGTS survey through cross-correlating with TESS TOIs Through cross-correlating TESS Objects of Interest with NGTS survey fields, we noticed that some TOIs are not always independently discovered by NGTS. This is often due to a shallow transit depth, close to the signal-to-noise limit of NGTS (~1mmag), and/or limited in-transit NGTS data. After using the TESS ephemeris and period to phase-fold the NGTS data, we have recovered over 25 previously overlooked transiting planet candidates in the NGTS survey. Owing to the shallower transit depths, around half of these previously missed candidates are Neptune and sub-Neptune sized, some in multi-planet systems. Through combining TESS and NGTS data, alongside other ground-based photometric follow-up, the number of transits and the baseline of observations can be greatly extended, particularly where NGTS data precedes the TESS data, in some cases by several years. This leads to improved ephemerides, and potentially improves estimates of planetary radii and other parameters. It is also beneficial for multi-planet systems, aiding the search for additional planets or assessing the data for Transit Timing Variations.
1.33 Isaac S. Narrett MIT HST and TESS point to a highly spotted photosphere for HD189733A Transmission spectra can be affected by stellar photospheric heterogeneities that alter transit depths. The HD189733 system provides a clear example of this challenge, with features variously interpreted as signatures of scattering by haze in the planetary atmosphere or unocculted starspots. Here, we use three Hubble datasets to directly infer the spot covering fraction of HD189733A and explore the evidence for photospheric heterogeneity in the out-of-transit spectra. We model the stellar spectrum using 1–3 spectral components, finding that a two-component model (photosphere and spot) is preferred for all datasets. We find photospheric and spot temperatures of ~5295 K and ~3222 K, respectively, which are consistent across datasets. The spot covering fraction is large and varies between ~38% and ~47%. Combined with time-domain insights from TESS data revealing HD189733A's 1.4% peak-to-peak variability, our findings imply that the majority of the spots must be distributed axisymmetrically, e.g., in a densely filled latitudinal band or at the poles. This work underscores the importance of considering axisymmetric spot distributions in analyses of transmission spectra and the unique role that TESS plays in this effort.
1.34 Ana Glidden MIT JWST-TST DREAMS: Preliminary Reconnaissance of TRAPPIST-1e with JWST NIRSpec PRISM With JWST, we are finally able to probe the atmospheres of small, temperate exoplanets that may host life. TRAPPIST-1e has held particular interest for both expert and non-expert audiences alike as it is one of our best potentially habitable targets. As part of the JWST GTO Exoplanet Transit Spectroscopy Team (#1331, PI: N. Lewis), we observed four transits of TRAPPIST-1e with NIRSpec PRISM from 0.6 to 5.3 microns at low resolution (R ~30-300). Our observations serve as the first preliminary reconnaissance of the planet with JWST. With our new data, we can place stronger constrains on the mean molecular mass of the atmosphere and evaluate strategies to separate the planetary and stellar contributions. As part of the Deep Reconnaissance of Exoplanet Atmospheres through Multi-instrument Spectroscopy (DREAMS), this work lays the groundwork for planned future observations of the system.
1.35 Canis Li Valley Christian High School A Search for Temporal Atmospheric Variability of Kepler and TESS Hot Jupiters We perform a systematic search for atmospheric variability in short-period gas-giant planets (hot Jupiters) observed by the Kepler and TESS missions, by looking for temporal variability of their secondary eclipse depths. This is motivated by a recent detection of a decrease in the dayside brightness of brown dwarf KELT-1 b between TESS Sectors 17 and 57, separated by about 3 years. We fit the Kepler light curves of 53 hot Jupiters and measure their secondary eclipse depths during individual Kepler quarters and 4-quarter windows. We detect the secondary eclipses in individual quarters or four-quarter windows for 17 out of the 53 systems. In those 17 systems we do not detect statistically significant astrophysical variation in the secondary eclipse depths. This absence of detected secondary eclipse variability in Kepler data suggests that the atmospheric variability in KELT-1 b is not common. In addition, several of the 53 targets we investigated display variability in their transit depths with a period of 4 quarters (1 year). This instrumental signal is likely present in the light curves of other transiting planets and other variable stars observed by Kepler. We perform a similar analysis with TESS data and discuss our findings.
1.36 Gavin Wang Johns Hopkins University A Blind Search for Transit Depth Variability with TESS Transiting exoplanets are one of the largest and most well-studied populations of exoplanets. Typically, the depth of a transit, which is the fraction of light blocked by a planet as it crosses the face of its host star, is assumed to be time-independent. However, such depths could—and have been found to—vary over time through mechanisms including stellar activity and orbital dynamics. In this talk I will present a search for transit depth variability within a sample of 330 known exoplanets observed by TESS. I will discuss the transit light source effect, which arises from the inhomogeneity of stellar surfaces, and how it could give rise to transit depth variations in both wavelength and time. Motivated by the fact that this effect is expected to be stellar type-dependent—and, in particular, more prominent for M dwarfs—I will present a search for population-level correlations between transit depth variability and stellar type. Finally, I will present individual systems that show significant transit depth variability and discuss the implications of our work in light of the upcoming Roman mission.
1.37 Harshitha M Parashivamurthy University of Chile Super Earths around super small stars. TESS has discovered more planet candidates than known exoplanets, opening a unique opportunity for population studies. Most small planets are expected to be discovered around K stars, and many earth-sized planets around M dwarfs. With this increased observation of small stars, we finally have a good opportunity to study the small planets around these stars. We want to investigate how planet size scales with stellar properties to test models of planet formation and evolution. To do this, we are building a homogeneous stellar and planet catalog with the help of GAIA for the M and K dwarfs, which are currently lacking. With these updated stellar parameters, the first step is to update the radius valley to examine the variations in the ratio of sub-Neptunes to super-Earths from K to M dwarfs. To further understand the dependence of planet size on stellar mass, we calculate the occurrence rates of super-Earths around small stars. We plan to do this by determining a detection recovery rate for TESS and developing an accurate detection efficiency model for all TESS transits.
1.38 Will James Brennom Harvard-Smithsonian Center for Astrophysics Toward a Homogeneously Analyzed Hot Jupiter Population: Reanalysis of Twenty-Two Ground-Based Hot Jupiter Discoveries Due to heterogeneous data sources and methodologies, demographic analysis of the hot Jupiter population suffers from inflated noise and potential bias. This makes it difficult to discern statistical subtleties; e.g. in the eccentricity distribution, which bears the imprint of migration mechanisms and can help quantify the prevalence of competing hot Jupiter evolutionary pathways. While previous works have carried out reanalysis of some planets already, the availability of TESS and Gaia data for nearly the full sky provides us with the first opportunity to refine the analysis of the entire hot Jupiter population using high quality, homogeneous datasets and a consistent methodology. As a first step in this effort, we present our methodology and preliminary results from a sample of twenty-two hot Jupiters with periods >5 days. With the EXOFASTv2 software package, we fit TESS 2-minute light curves, Gaia DR3 parallaxes, broadband photometry, all-sky dust maps, and published radial velocities to derive new stellar, planetary, and orbital properties. We compare our results to published values and discuss the potential for ensemble analysis using the full sample in future work.
1.39 Catherine Clark NASA JPL, Caltech/IPAC A Catalog of Companions to TESS Objects of Interest Roughly half of exoplanet-hosting stars are binary, yet planets in binaries are often ignored. Stellar companions can influence multiple facets of planet formation and evolution, resulting in distinct properties for planets around single stars and in close-in and wide binaries. High-resolution imaging has become standard practice in the vetting of planetary candidates, and our group has become one of the largest providers of these images. This imaging has led to the discovery that unseen companions affect our ability to characterize – or even completely obscure – small planets. We have therefore compiled a catalog of companions to TESS Objects of Interest. These stars have been vetted via adaptive optics imaging, revealing close-in stellar companions or identifying likely single stars. This catalog also includes wide, common-proper-motion companions. After vetting the companions for boundedness, we investigate planet properties such as radius and orbital period in these subsamples of confirmed and candidate planet hosts, including as a function of stellar temperature. This catalog will be of fundamental utility to both exoplanet scientists and stellar astrophysicists using the wealth of TESS data to probe the Solar Neighborhood.
1.40 Preethi Karpoor University of California San Diego No Dearth for Earths: Unveiling the Earth+super-Earth Occurrence Rate in M Dwarfs via Magnitude-Limited Samples M dwarfs not only dominate the stellar population in the solar neighborhood but also host the majority of terrestrial planets in our galaxy. However, there is a gap in our understanding of the variation of planet occurrence rate with stellar mass, especially for stars with M<0.3 M⨀. Some studies indicate that the terrestrial planet occurrence rate peaks at the lowest-mass stars, however, pebble accretion models predict the peak yield for stars with M~0.5 M⨀ with a decreasing occurrence for lower-mass hosts. Here we determine the Earth+super-Earth occurrence rate for a magnitude-limited sample of mid-to-late-M dwarfs observed with TESS. We have developed the Exoplanet Survey & Characterization Program for Earth-like Rocky planets (EXOSCAPER) pipeline for detecting multi-planetary systems using TESS lightcurves. We present 17 new candidates & validate 35 known planetary candidates within the Earth+super-Earth range. We also investigate the precision and planet detection efficiency as a function of lightcurve cadence,using 20, 120, and 200-sec data from TESS. We compute the cumulative occurrence rate = 0.24-0.78+0.36 planets/star for a radius range of 0.2-2 R⊕ and periods between 0.1-7 days.
1.41 Samuel Grunblatt Johns Hopkins University Extending the Exoplanet Frontier: uncovering the evolution of hot Neptunes with TESS Hot Neptunes, gaseous planets smaller than Saturn (~ 3-8 R_Earth) with orbital periods less than 10 days, are rare. Models predict this is due to high-energy stellar irradiation stripping planetary atmospheres over time, often leaving behind only rocky planetary cores. Here, we present the detection of several new hot Neptune candidates transiting post-main sequence stars using our TESS full frame image pipeline, giants. We also present radial velocity measurements for one of these candidates, confirming its planetary nature and constraining its mass and average density. The old age and high equilibrium temperature yet remarkably low density of this planet (rho_p = 0.58 +0.30/-0.20 rho_Jup) suggests that the gaseous envelope of this planet should have been stripped by high-energy stellar irradiation billions of years ago. Unexpectedly low stellar activity and/or late-stage planet inflation could be responsible for the observed properties of this system. Further studies of these systems with more ground-based radial velocities and precise photometry in multiple pass bands will provide new insight into the evolution of the atmospheres of small planets.
1.42 Xinyan Hua Department of Astronomy, Tsinghua University Metal-rich stars tend to host misaligned planets with higher mutual inclinations Stellar metallicity is strongly correlated with the occurrence of certain types of planets or planetary system properties. In this study, we present a correlation between stellar metallicities and the mutual inclinations of multi-planet systems, suggesting that metal-rich stars host planetary systems that are dynamically hotter. After investigating 150 targets with measured mutual inclinations, we observed that planets orbiting metal-rich stars tend to exhibit more dispersed mutual inclinations. Moreover, there is no clear evidence linking the high mutual inclination of these inner small planets with the existence of outer gas giants, though more data are needed to draw any definitive conclusions. We also observed a similar trend in the stellar mass - mutual inclination space, which is not as significant as with stellar metallicity. We hypothesize that such systems accumulate more material within their protoplanetary disks, leading to a more intensive dynamical evolution process that can perturb the planets into misaligned orbits, resulting in higher mutual inclinations. Planet formation and population synthesis models tracking the evolution of mutual inclinations would be needed to provide an explanation for this correlation.
1.43 Emma Dugan Indiana University Universal Misalignments of Sub-Saturns Regardless of Stellar Temperatures and Orbital Periods Stellar obliquity measurements for Jupiter-sized planets reveal two patterns: cooler stars typically host hot Jupiters on aligned orbits, while hotter stars with hot Jupiters often show misalignments; additionally, hot Jupiters are more misaligned than their warmer counterparts. These observations underscore the importance of obliquity measurements for smaller planets like sub-Saturns, which provide a critical layer of constraints on the mechanisms driving spin-orbit misalignments, sensitive to planetary mass. The detection of sub-Saturns, especially warm ones, has been challenging due to their low occurrence and lower SNRs compared to larger gas giants. The TESS mission has significantly advanced this field by providing a statistically meaningful sample of sub-Saturns around bright stars. We present two new measurements of warm sub-Saturns, both misaligned, which, when combined with archival data, show that sub-Saturns are universally misaligned regardless of stellar temperature or orbital period. This discovery allows us to probe stellar obliquity in a previously uncharted domain, introducing a compelling new puzzle and imposing significant constraints on our understanding of the origins and evolution of spin-orbit misalignment.
1.44 Brandon Radzom Indiana University Evidence for Primordial Alignment: Insights from Stellar Obliquity Measurements for Compact Giant Systems Stellar obliquity provides valuable insight into the formation and evolution of exoplanetary systems. Yet, it remains unclear whether observed spin-orbit misalignments for hot Jupiters are driven primarily by high-eccentricity migration — expected to have occurred for short-period, isolated planets — or a more universal process that affects a variety of systems. Compact multiple-planet systems, for which few stellar obliquity studies have been conducted, are critical to differentiate between these hypotheses, as their tightly-packed configurations are inconsistent with the violent dynamics inherent to high-eccentricity migration, allowing them to trace the primordial disk plane. The precision time-series photometry obtained by TESS for a large number of stars has greatly expanded the sample of giant planets in compact systems orbiting bright stars. We report Rossiter-McLaughlin measurements for three such planets: two sub-Saturns, TOI-5126 b and TOI-5398 b, and one hot Jupiter, TOI-5143 b. All three are aligned. When combined with archival data, our results demonstrate a strict trend of alignment for compact systems, providing strong support for primordial alignment and post-disk misalignment via high-eccentricity migration.
1.45 Sam Christian MIT Wide Binary Orbits are Preferentially Aligned with the Orbits of Small Planets, but Probably Not Hot Jupiters Studying the relative orientations of the orbits of exoplanets and wide-orbiting binary star companions can shed light on how planets form and evolve in binary systems. Using data from Gaia DR3 and TESS, we find that the orbits of small planets ($R_{\ocross}<6$) are well-aligned with the orbits of the binary systems they reside in for binary semimajor axes less than 700 AU. We find no evidence for alignment above 700 AU regardless of planet size. We also find no evidence for alignment in our sample of large, closely-orbiting planets (mostly hot Jupiters) at any separation. We argue that despite selection effects, the alignment between wide-binary and hot Jupiter orbits is probably not as strong as wide-binary and small planet orbits. We will discuss the implications of these findings on the evolution of planets in binary systems, and propose a disk torque mechanism that can explain the alignment we see.
1.46 Konstantin Gerbig Yale University Aligning Planet-Hosting Binaries via Dissipative Precession in Circumstellar Disks Recent observations have demonstrated that some subset of even moderately wide-separation planet-hosting binaries are preferentially configured such that planetary and binary orbits appear to lie within the same plane. In this talk, I explore the prospects for viscous dissipation during the protoplanetary disk phase, induced by disk warping as the system is forced into nodal recession by an inclined binary companion, as a possible avenue of achieving orbit-orbit alignment. We analytically model the coupled evolution of the disk angular momentum vector and stellar spin vector under the influence of a distant binary companion. I show that a population of systems with random initial orientations should appear detectably more aligned after undergoing dissipative precession. In addition, the presented framework naturally reproduces the observed stellar obliquity distribution and predicts that circum-primary planets in systems with high stellar mass ratios should be preferentially less aligned than planets in equal-mass stellar binary systems. We discover this trend in TESS and Gaia DR3 data, and thus conclude that dissipative precession likely plays a role in sculpting orbital configurations in planet-hosting binaries.
1.47 Chenyang Ji Tsinghua University The TOI Solar Analog Spectroscopic Survey High-resolution spectroscopy has revealed that the Sun is depleted in refractory elements compared to other nearby solar analogs, and the existence or ingestion of planets are believed to leave such chemical imprints on their host stars. Previous works have quantified this solar chemical anomaly by defining a slope in abundance [X/H] as a function of condensation temperature, known as the Tc trend (Meléndez et al. 2009, Bedell et al. 2018). Various scenarios have been proposed to explain its nature, including solids locked up by terrestrial planets (Chambers 2010), trapping of dust by giants (Booth & Owen 2020) and planet engulfment (Oh et al. 2018). The TOI Solar Analog Spectroscopic Survey will follow up ~80 TOIs that host known planets or candidates using high-quality spectra taken by Magellan MIKE and EXPRES on Lowell Discovery Telescope. We will identify alternative indicators aside from the Tc trend to explore links (or lack of) between planet existence and chemical abundances of host stars.
1.48 Tianjun Gan Université de Montréal Investigating the formation and evolution channel of giant planets around M dwarfs With the highest planet-to-star mass ratio of any type of planetary systems, giant planets around M dwarfs are extreme cases that serve as sensitive probes of planet formation. In this talk, I will present our statistical studies on the stellar metallicity and occurrence rate of such systems. I will first show the findings of our TESS-SpeX survey that homogeneously characterize a sample of M dwarfs with giant planets, and compare the metallicity distribution with field M dwarfs as well as FGK-host analogues to probe their formation history. I will also talk about our occurrence rate measurement of hot Jupiters around M dwarfs based on the TESS Primary Mission. Combining with hot Jupiter occurrence rate measurements around FGK stars from TESS and statistical results from CLS, I will introduce a new statistic indicator "relative occurrence rate between hot and cold Jupiters" that might be able to trace the migration of gas giants. Finally, I will briefly summarize the preliminary results of our TESS systematic search program based on four-year data, focusing on warm Jupiters around mid-to-late M stars.
1.49 Khalid Barkaoui University of Liège MANGOS: M-dwarfs Accompanied by close-iN Giant Orbiters Transiting giant planets around M-dwarf stars are extremely interesting scientific targets for the field of exoplanetary science. The relatively small size and low mass of their host stars leads to large transit and radial-velocity signals. Moreover, giant planets around M dwarfs are still quite rare - the core-accretion model does not readily form giant planets around M-dwarfs. So far, only twenty systems have been found. Such systems are prime targets for detailed atmospheric characterization through transmission spectroscopy with JWST space telescope. This allows us to study the composition and properties of the planet's atmosphere, and make a link to its formation and evolution mechanisms. In this talk, I will describe our observing strategy making use of the full SPECULOOS and TRAPPIST networks, supported by a program on ESPRESSO to measure masses. I will also present exciting results from the first two years of the survey.
1.50 Jack Schulte Michigan State University The Migration and Evolution of giant ExoPlanets (MEEP) Survey Since the discovery of 51 Pegasi b, over 550 hot Jupiters (HJs) have been confirmed. These discoveries were made by a wide variety of ground-based and space-based surveys using many different, independent, analysis techniques. While this has been useful for confirming the validity of the discovered HJs, it has produced a sample that is plagued by unquantifiable selection biases, differing assumptions, and a lack of self-consistency. To address these issues, we aim to discover and characterize all remaining detectable HJs orbiting bright (G < 12.5 mag) FGK stars using TESS and homogeneous analysis techniques. This large-scale, collaborative, discovery effort will be combined with smaller-scale characterizations of benchmark systems that show signs of youth, planetary engulfment, and other features associated with dynamical instability. Armed with a complete, self-consistent, magnitude-limited sample of HJs and several critical benchmark systems, we will be able to comprehensively address the question of how HJs form and evolve. I will present the detailed characterization of the first dozen discoveries from the MEEP survey, and provide an early glimpse into the current population of hot Jupiters from TESS.
1.51 Javier Viaña Massachusetts Institute of Technology SCOOP: A Pipeline for Distinguishing On-Target and Off-Target Signals in TESS Data One area of disagreement in human vetting efforts of TESS data is the determination if a transit signal is coming from the target star or not (on-target vs. off-target). Because flux data from TESS comes in discrete pixels, identifying the location of the source of a transit signal can be very difficult and is often up to subjective interpretation. In this work we present a pipeline based on a branched convolutional neural network that efficiently determines whether or not a candidate is on-target. We named this pipeline SCOOP: Star Classifier for On & Off-target Predictions. SCOOP uses as inputs both a reference out-of-transit, the on-transit images of the target star, and a feature matrix that mixes the information of these two. The pipeline encodes these three matrices by separate 2-d convolutional branches of a network, together with various 1-d features of the star. The outputs of all the branches are then concatenated and passed through a final set of dense layers, producing a single output value that represents the probability of being on target. Our ensemble of models currently achieves over 88% accuracy on the test set. Current efforts are focused on integrating SCOOP in the Astronet pipeline to enhance its performance.
1.52 Eoin O'Connor University of York Automating Exoplanet Discovery: Enhancing Transit Method with Deep Learning and Transformers The transit method, which detects exoplanets by observing periodic dips in stellar brightness, has significantly advanced our understanding of distant solar systems. This work enhances this method by integrating machine learning with TESS data to automate the identification of exoplanets and other celestial phenomena. Traditional models including k-means, random forest, and decision trees serve as baselines for performance comparison against two deep learning architectures: A Convolutional Neural Network (CNN) and a Transformer model. CNNs have excelled in recognizing patterns in data, such as transit signals in light curves, achieving higher accuracy and lower false positive rates than previous methods. Integrating Transformers marks a novel development in astronomical research. Pivotal in natural language processing and subsequently across domains, Transformers bring sophisticated attention mechanisms that enhance model interpretability particularly effective in unveiling weak signals that conventional models often overlook. This promises to improve current discovery techniques and deepen our understanding of the dynamics and compositions of distant planetary systems, paving the way for significant astronomical discoveries.
1.53 Zoë Luca de Beurs Massachusetts Institute of Technology How TESS and machine learning can mitigate stellar activity in radial velocity observations TESS requires precise radial velocity (RV) measurements to achieve its key science goal of measuring the masses of a large sample of transiting sub-Neptunes and super-Earths, enabling studies of their compositions and atmospheres. RVs can also recover lost ephemerides and allow further characterization that transits alone cannot achieve. However, these science goals require extremely high RV precision, which is currently limited by stellar variability caused by inhomogeneities on the stellar surface like starspots and faculae. Here we show that machine learning techniques significantly improve RV precision by separating the stellar activity from real Doppler shifts, reducing the RMS by 40% for the Sun. We found a similar improvement in RMS for other stars and used this technique to add to TESS’s sample of planets with precise masses. We also find that adding lightcurves to our neural network enhances its ability to model stellar variability for the Sun. This means that TESS lightcurves could be a major ingredient in solving the stellar activity problem for other stars. Going forward, these techniques will help measure the masses of transiting planets and may eventually help us detect habitable-zone Earth-mass exoplanets.
1.54 Dax Feliz American Museum of Natural History NEMESIS: Exoplanet TraNsit SurvEy of Nearby M-dwarfs in TESS FFIS II The Transiting Exoplanet Survey Satellite (TESS) has observed over 20 million stars brighter than TESS magnitude 13.5 using Full-Frame Images (FFIs). However, many M-dwarfs are fainter than TESS magnitude 13.5, and were only observed with 30-minute cadences, rather than 2-minute cadence observations. FFI transit surveys provide empirical insights into the types of planet detections that were missed due to TESS’ observing mode strategy for faint M-dwarfs. Using the NEMESIS pipeline, we analyze ∼191,000 FFI light curves from nearby M-dwarfs (<100 pc) in Sectors 1–26. Our analysis integrates both automated vetting tests and manual inspection to identify promising planet candidates. Additionally, we examine our transit detection sensitivity and survey completeness to derive integrated occurrence rates of M-dwarf planets across various orbital periods and planetary radii ranges. The detections of new planet candidates through this ongoing project will significantly enhance TESS’s ability to improve the statistical power of demographic studies concerning the types of exoplanets orbiting these low-mass stars.
1.55 Marina Lafarga Magro University of Warwick Automatic search of new candidates in the TESS FFI SPOC lightcurves in a uniform sample of well-characterised main sequence stars TESS has enabled the identification of thousands of planet candidates and hundreds of confirmed planets, opening up the possibility of demographic studies. However, the process of transit vetting and further confirmation of planet candidates is subject to time-consuming and biased manual inspection, highlighting the need for automatic pipelines. In this work, we perform statistical validation of planet candidates around main sequence stars with the new pipeline RAVEN, which allows for an entirely automated process from discovery to validation. We target all main sequence stars present in the TESS FFI SPOC ligthcurves characterised by Gaia (with Gaia magnitude brighter than 14, over 2.3 million targets). We conduct a BLS search on all SPOC FFI lightcurves and use RAVEN to vet and validate planet candidates. RAVEN probabilistically classifies transit candidates into planet candidates and false positives using machine learning algorithms trained with realistic synthetic lightcurves. We expect to be able to statistically validate multiple new planet candidates, enabling demographic studies in a uniform and well-defined sample.
1.56 Malia Barker Boise State University Doomed Worlds—A Tool for Detecting Tidally Decaying Exoplanets Hot Jupiters, large, hot exoplanets with very short periods, are being pulled into their host stars. Due to their proximity to their host stars, the planets’ host stars exert a tidal force on the planets. Angular momentum is transferred from the orbit, and the orbital periods decrease in a process known as tidal decay, leading to the planet’s eventual destruction. With transit timing observations, we can observe these changes in the orbital period. Changes in orbital period are very small, milliseconds per Earth year, making tidal decay difficult to detect. By building our proposed Python package susie, we can use transit observations and statistical models to determine if an exoplanet is experiencing tidal decay, and we can build future observing schedules for astronomers to maximize the prospects for detecting tidal decay. With susie, we can find more planets that are falling into their host stars and meeting their inevitable demise.
1.57 Elisabeth R. Adams PSI Where are the tidally decaying planets? Ultra-hot Jupiters are likely doomed by tidal forces to undergo orbital decay and eventual disruption by their stars, but the timescale over which this process unfolds is unknown. We present results from a long-term project to monitor ultra-hot Jupiter transits. As anticipated, we easily detected orbital decay by WASP-12 b in agreement with prior work. Five of the other forty-two systems monitored initially showed promising non-linear transit ephemerides; however, two of those were found to result from multiple independent errors in the literature timing data. None of the other three are likely to be decaying: two have increasing orbital periods that rest on a small handful of points (WASP-121 b and WASP-46 b) and the rate of apparent period decrease for the last one is too rapid to be explained by orbital decay (TrES-1 b). For nearly half of our full sample (20 of 42 planets) we can rule out dP/dt as high as observed for WASP-12 b. While many ultra-hot Jupiters could still be experiencing rapid decay that we cannot yet detect, a sizable sub-population of UHJs are decaying at least an order of magnitude more slowly than WASP-12 b.
1.58 Daniel Bayliss University of Warwick Discovering Non-Transiting Exoplanets with TESS Hidden within TESS light-curves are the signatures of non-transiting exoplanets, via the subtle effects of reflection/emission, tidal ellipsoidal distortion, and Doppler beaming. For the first time, we search for these signatures in 140,000 bright dwarf stars in the southern ecliptic hemisphere of the TESS mission. We find 27 candidate signals that may be attributed to short-period, massive planets. Our candidates have periods ranging from 0.74 to 1.98 days, and amplitudes ranging from 94 to 528 ppm. The host stars are all bright (T<11). We are now following-up these candidates with high precision radial velocity measurements from HARPS and hight precision photometry from CHEOPS.
1.59 Prajwal Niraula MIT Decrypting the Secrets of Kepler's Heartbeat Systems Heartbeat systems provide a unique corridor to understand high eccentricity migration scenarios through tides. Here, we report the discovery of dozens of previously unreported Kepler heartbeat systems leveraging three independent algorithms: Phase Dispersion Minimization, Inverse Transit Search, and Neural Nets-based classifier. We have aimed to create the most comprehensive catalog of the Kepler heartbeat systems and optimize the individual algorithms to improve their sensitivity to hunt for companions that could be planetary in origin. Using the new population Kepler heartbeat targets, we look for the tidally excited oscillations and leverage neural nets to understand the patterns amongst the pulsations. We further leverage these patterns towards building an accurate Neural net classifier to see if the pulsations themselves could be used to robustly detect an eccentric companion, particularly for $\delta$-Scuti targets. Our algorithms can easily be extended to work for TESS.
1.60 Jiaxin Tang Tsinghua University RVxTESS I: Modeling Asteroseismic Signals with Simultaneous Photometry and RVs With growing availability of high-precision radial velocity (RV) spectrographs (down to cm/s), detecting low-mass exoplanets at cm/s level now hinges on mitigating stellar jitter, which introduces noise at m/s level. Contemporaneous high-precision photometry uniquely enabled by TESS guides RV modeling to separate intrinsic stellar variations from planetary signals, motivating the RVxTESS project (rvxtess.com). Our study examines the asteroseismic signals of HD 5562, a subgiant observed by TESS and Magellan/PFS. We used Gaussian Process (GP) regression on the simultaneous photometric and RV data to model its stellar jitter. Using GP trained by TESS data, we reduced RV scatter from 2 m/s to 0.5 m/s. With good RV sampling, GP is more effective at noise reduction than conventional binning. An injection-recovery test shows that the planet mass detection limit around HD 5562 can improve by a factor of 3, down to 3 Earth masses in most optimistic scenarios. Our work demonstrates that TESS photometry can help mitigate stellar jitter from asteroseismic signals. TESS's longevity and full-sky coverage offer potential for similar applications on more stars in the future.
1.61 Li Zeng Harvard University, Department of Earth & Planetary Sciences Cosmic hydrogen and ice loss lines We explain the overall equilibrium-temperature-dependent trend in the exoplanet mass–radius diagram, using the escape mechanisms of hydrogen and relevant volatiles, and the chemical equilibrium calculation of molecular hydrogen (H2) break-up into atomic hydrogen (H). We identify two Cosmic Hydrogen and Ice Loss Lines (CHILLs) in the mass–radius diagram. Gas disks are well known to disperse in ten million years. However, gas-rich planets may lose some or almost all gas on a much longer timescale. We thus hypothesize that most planets that are born out of a hydrogen-gas-dominated nebular disk begin by possessing a primordial H2-envelope. This envelope is gradually lost due to escape processes caused by host-stellar radiation.
1.62 Yao Tang UC Santa Cruz A Reassessment of Core-Powered Mass Loss for Sub-Neptunes The population of planets below 4 Earth radii is split into two populations: sub-Neptunes, the low density planets with a H/He envelope atop the core, and super-Earths, which are envelope-free rock/iron cores. A popular explanation for the dichotomy is that some sub-Neptunes undergo strong atmospheric escape that strips away their entire H/He envelopes, eventually evolving into super-Earths. However, the relative roles of i) stellar XUV-driven escape, ii) long-term``core-powered” mass loss (CPML) from interior cooling, and iii) post-formation ``boil-off” at young ages, is still unclear. We have developed a new python-based one-dimensional interior and evolution model with both early boil-off and CPML allowing us to assess the importance of CPML. With a boil-off phase that provides proper initial conditions for the later planetary evolution, we find that CPML has little impact on the demographics of the exoplanet population, as opposed to the previous studies. We directly compare our results to the previous analytic work on CPML with particular attention to assumptions made about a range of important physical processes, and identify simplifications that cause this large difference with previous work.
1.63 Michael Greklek-McKeon California Institute of Technology The TESS TTV Follow-up Program: Revealing Volatile-Rich Terrestrial Planets Around M Stars Models predict that water-rich planets may be common around low-mass stars, but definitive evidence for the existence of water worlds has remained elusive. Recent JWST observations of sub-Neptune sized planets orbiting nearby M dwarfs found atmospheres enriched in CH4, CO2 and H2O, but the enrichment mechanism is debated. To answer this question, it’s important to know if these two planets represent the broader population of sub-Neptunes, and to quantify the range of possible sub-Neptune atmosphere types. A first step is to constrain the volatile atmospheric mass fractions of more small planets, which requires precise planetary masses and radii. For near-resonant multi-planet systems exhibiting transit timing variations (TTVs), we can measure these planetary bulk densities. TESS has detected many such systems and obtained an initial set of TTVs, which we use as the basis for extensive follow-up. We have combined dozens of ground-based transits with TESS data to characterize six multi-planet M dwarf systems. Our preliminary survey results reveal several new small volatile-rich worlds, including some that are top candidates for atmospheric characterization with JWST and some of the coldest known volatile-rich rocky planets.
1.64 Toby Rodel Queen's University Belfast Putting a TIaRA on SPOC: predicting long-period planet yields from TESS TESS is generally biased towards shorter period planets due to the lower probability of transit and its relatively short observation window leading to many longer period planets only being seen as a single transit or “monotransit”. We have created the Transit Investigation and Recoverability Application (TIaRA) pipeline, a tool for measuring the ability of TESS to detect planets. We then combine sensitivity maps created using TIaRA with occurrence rates derived from Kepler to obtain yield estimates for TESS. We predict 2271+241−138 planets should be detectable from the Year 1 and Year 3 SPOC FFI lightcurves. We find a ~75% deficit of planets with periods >25 days in the TOI catalogue compared to our yield predictions at a confidence level of > 3𝜎. This indicates a significant number of long-period planets yet to be discovered from TESS data.
1.65 Emma Page Lehigh Univsersity Giants, Boxes, and Forests: Hunting Exoplanets Transiting Evolved Stars Only ~6% of known transiting planets orbit evolved host stars. Discovering more will allow us to test if the population of planets orbiting main sequence stars is similar to those orbiting evolved stars. Exoplanet transits around evolved stars generally have longer durations and shallower depths than transits around main sequence stars, and evolved stars can have different photometric behaviors than main sequence stars. As a result, transits around evolved stars may be missed by main sequence transit searches. Our team developed the giants pipeline, which reduces Transiting Exoplanet Survey Satellite (TESS) light curves to search for long duration, shallow transits around evolved stars. We combine observational parameters from the Box Least Squares (BLS) algorithm with host star properties as input parameters, and train a random forest model to categorize light curves as potential planet candidates or non-detections. We search through the smaller sample of predicted candidates by eye to further vet the light curves and choose targets for follow up observations. Using this giants, boxes, and forests planet hunting method, we have begun to confirm new planet detections transiting evolved stars.
1.66 Yuchen(Elina) Zhang Institute for Astronomy, University of Hawaii Characterizing Old and Young Transiting Brown Dwarfs in the "Mass Desert" with TESS Brown dwarfs (BDs) are defined by mass to be in between stars and giant planets, so they are vital to study for a better understanding of how objects change across the planet-to-star mass range. Compared with planetary and stellar companions, the BD demographic has relatively low occurrence of short-period companions to main-sequence host stars. This unique characteristic is called the “Brown Dwarf Desert''. The currently known transiting BD sample is still scant but rapidly growing, thanks to the TESS mission. However, there is an apparent lack of objects at ~30Mj. I will present two low-mass transiting BD systems discovered by TESS, TOI-4776 and TOI-5422, located in the under-populated region of the BD mass-radius space. They have different ages. The younger and larger BD is TOI-4776.01 at ~33.9Mj and ~1.06Rj, orbiting a late-F star ~4.3Gyr old in a 10.42 day period. The older TOI-5422.01 is ~25.4Mj and ~0.9Rj in a 5.38 day orbit around a sub-giant star ~9.8 Gyr old. Compared with substellar M-R evolution models, TOI-5422.01 agrees well with models, which is not commonly seen, while TOI-4776.01 is inflated. Besides, TOI-5422 shows apparent photometric modulations with a rotation period of ~10.75 day found by a rotation analysis.
1.67 Theron Carmichael University of Hawai'i Exploring the Transiting Brown Radius Anomaly with TESS This work explores the discrepancies between the transiting brown dwarf (BD) population and substellar age-radius models by examining radius inflation mechanisms in BDs and giant planets as a function of mass. Over 40% of confirmed transiting BD systems to date have been discovered by TESS, highlighting the mission’s substantial impact on this population. To better understand the radius discrepancies seen in transiting BDs, I compare the relative ages of over 90% of known transiting BDs via a homogeneous analysis of their host star ages. For the first time, this enables us to compare the relative ages of transiting BD host stars for the vast majority of known transiting BDs to more carefully examine the emerging trend of the “brown dwarf radius anomaly”. In particular, both low-mass (13-25MJ) and high-mass (70-80MJ) brown dwarfs show clear signs of radius inflation at ages beyond 1 Gyr, but it is unclear whether or not the inflation mechanisms, such as high incident flux from the host star, are shared between them. Here I discuss several possible radius inflation mechanisms affecting transiting brown dwarfs and contextualize them with transiting giant planets and substellar evolutionary theory.
1.68 Alicia Kendall University of Leicester NGTS Contributions to the Brown Dwarf Desert The brown dwarf desert is a known paucity of transiting brown dwarfs orbiting main sequence stars within 5 AU, and is thought to be linked to the tails of two formation mechanisms, meaning these systems may have formed like a planet or like a binary system. Using the Next Generation Transit Survey (NGTS) we have discovered 4 systems (e.g. Jackman et al., 2019; Acton et al., 2021; Henderson et al., 2024a, 2024b), a tenth of those known to be in the desert to date. In this talk I will review the NGTS contribution to mapping the brown dwarf desert, and highlight 2 discoveries: NGTS-28b, one of the hottest and shortest period systems within the desert, and TOI-2490b, a high mass BD on an HD80606b-like orbit with an eccentricity of 0.8.
2.01 Andres Luengo Yale University Asteroseismology of Unresolved Stellar Populations Stellar ages from asteroseismology is a key ingredient in understanding the history of the Milky Way. We compare the integrated light of synthetic stellar populations with observations of unresolved sources observed by TESS, and analyze the potential of using pixel variability to determine the ages of these unresolved populations.
2.02 Marc Hon MIT sigma Draconis: The coolest nearby star with asteroseismology from the Keck Planet Finder and TESS Asteroseismology of dwarf stars cooler than the Sun is very challenging due to the low amplitudes and rapid timescales of oscillations. Here, we present the asteroseismic detection of solar-like oscillations at 4-minute timescales in the nearby K-dwarf sigma Draconis using extreme precision Doppler velocity observations from the Keck Planet Finder and 20-second cadence photometry from NASA's Transiting Exoplanet Survey Satellite. The star is the coolest dwarf to date with asteroseismic observations from both ground and space. The measured oscillations show excellent agreement with established luminosity-velocity amplitude relations and provide further evidence that mode amplitudes for stars cooler than the Sun scale more steeply with stellar luminosity than expected. By modelling the star's oscillation frequencies from photometric data, we measure an asteroseismic age of 4.5 Gyr, in agreement with values from literature. These observations demonstrate the capability of next-generation spectrographs and precise space-based photometry to extend observational asteroseismology to nearby cool dwarfs, which are benchmarks for stellar astrophysics and prime targets for directly imaging planets using future space-based telescopes.
2.03 Rebecca Spejcher Embry-Riddle Aeronautical University What Drives the Variability in Luminous Blue Variable Stars? Luminous blue variable stars (LBVs) are evolved massive stars with strong winds and large variability. The underlying mechanism driving the variability of these stars has not yet been determined. We used photometric data from TESS to study 30 LBVs (bona fide members and candidates) in the Large Magellanic Cloud. We performed Fourier transforms on the TESS data, allowing us to find the characteristic time scales and amplitudes of the variability. From these parameters, we are exploring how stellar characteristics, such as luminosity, color, and mass-loss properties correlate with properties of stellar variability. This can then be used to infer if internal gravity waves or stochastic processes such as subsurface convection drive the changes that we observe photometrically. We have also explored the TESS data for a small number of Galactic LBVs. While the Galactic light curves do not have the same duration as the sample from the LMC, these stars will help us determine if the driving mechanisms for variability in LBVs depends on the environment or metallicity.
2.04 Nobuyuki Kawai RIKEN / Tokyo Tech Optical Variability of Wind-Fed High Mass X-ray binaries: Insights from TESS Light Curves We have investigated the TESS light curves of eleven high-mass X-ray binaries (HMXBs) suspected to be powered by the accretion of stellar wind onto neutron stars. We observed significant optical variability in all of these systems. In some cases, we observed variations associated with the orbital period, suggesting tidal deformation of the companion. Comparison with X-ray data constrains the binary parameters and the size of the companion.
2.05 Tibor Mitnyan HUN-REN-SZTE Stellar Astrophysics Research Group, Baja Astronomical Observatory of University of Szeged, Hungary Eclipse-timing study of new hierarchical triple star candidates in the northern continuous viewing zone of TESS We compiled a list of more than 3500 eclipsing binaries located in and near the northern continuous viewing zone (NCVZ) of the TESS space telescope that have sufficient TESS photometry to search for additional hidden components in these systems. We obtained the TESS light curves of all targets in an automated way by applying convolution-aided differential photometry on the TESS full-frame images from all available sectors up to sector 60. We visually confirmed all of these light curves, determined the eclipsing periods of the objects, and calculated their eclipse-timing variations (ETVs). The ETV curves were used in order to search for nonlinear variations that could be attributed to a light travel-time effect (LTTE) or dynamical perturbations. We were able to fit a model solution for the ETVs of 135 hierarchical triple candidates, 10 systems of which were known from the literature, and the remaining 125 systems are new discoveries. We also compared the distributions of some orbital parameters from our orbital solutions with those from a previous Kepler sample. Finally, we verified the correlations between the available parameters for systems that have Gaia non-single star orbital solutions with those from our ETV solutions.
2.06 Ekrem Esmer Washington University The TESS Spotlight on Detached Binary Systems via Eclipse Timings Although binary stars are common in our galaxy, circumbinary planets are observationally challenging to detect relative to the planets orbiting single stars. We address this discrepancy by leveraging the wide sky coverage, long temporal baselines, and high cadence offered by TESS to conduct a comprehensive search for eclipse timing variations (ETVs) indicative of potential additional bodies as well as stellar spots and magnetic interactions. We select bright detached eclipsing binaries from the TESS Eclipsing Binary Catalog and infer mid-eclipse times using allesfitter, yielding a typical timing precision of $\sim$10 seconds for T$\sim$9 mag systems using two-minute cadence data. We catalog anti-correlations between the timings of primary and secondary eclipses as evidence of apsidal precession or the influence of stellar spots on the eclipse light curves. The resulting ETV catalog with robust timing uncertainties yields a database that can be used to establish mass limits for additional bodies in the system.
2.07 Ciarra Coston Emory University Characterizing Habitable Worlds Observatory Targets with TESS: Rotation Periods and Gyrochronological Age The Decadal Survey on Astronomy and Astrophysics 2020 (Astro2020) recommended that NASA begin to design a 6-meter-class UV/vis/IR space observatory (named Habitable Worlds Observatory, HWO) capable of imaging and spectrally characterizing potentially habitable exoplanets. HWO is slated to launch in the early 2040s and will target small, temperate exoplanets in the Habitable Zones of approximately 100 bright, nearby, Sun-like stars. To facilitate HWO precursor science efforts by the community, Mamajek & Stapelfeldt (2023) recently compiled the NASA ExEP Mission Star List for the Habitable Worlds Observatory of 164 candidate target stars. We analyzed time series photometry from TESS to determine rotation periods for candidate HWO target stars and to estimate gyrochronological ages. We report new TESS rotation periods for 35 of the ExEP HWO target stars and we were able to estimate gyrochronological ages for 20 of these stars. The ages for these stars range from ~0.1-1.5 Gyr, with the results biased toward the estimation of useful gyrochronoloy ages for the youngest, fastest-rotating, most active stars in the sample.
2.08 Jason Lee Curtis Columbia University MARMOT: Membership, Abundances, Rotation, and Magnetism Over Time The calibration of empirical ages based on rotation, chromospheric emission, and lithium requires data from benchmark star clusters. The large gap in age between the 120-Myr Pleiades and 700-Myr Praesepe can be filled by previously unappreciated clusters that now have enhanced memberships from Gaia. The MARMOT collaboration has targeted a dozen promising stellar structures warranting careful study. We measure periods with TESS and ZTF to complete the rotational census of each cluster, far exceeding what can be done with either survey alone. We then collect large samples of high-resolution spectra, with which we use to (1) establish new benchmark clusters for stellar astrophysics using newly derived metallicity and interstellar reddening values, (2) produce extensive kinematic, rotation, activity, lithium, and other abundance data for a large number of their members, and (3) retune rotation, activity, and Li clocks.
2.09 Luke Bouma Caltech The Empirical Limits of Gyrochronology Gyrochronology promises to infer a star's age from its rotation period and mass, but this promise is complicated by effects other than ordinary magnetized braking. We present a new interpolation-based gyrochronology framework that matches the time- and mass-dependent spin-down rates seen in open cluster data (Bouma, Palumbo & Hillenbrand 2023, ApJL). This includes the evolution of the dispersion in stellar rotation, in addition to the usual evolution of the mean rotation periods. The method is validated for 3800-6200 K stars aged between 0.08-4 Gyr. The age uncertainty floors vary strongly with stellar mass and age. Sun-like stars (5800 K) have uncertainties improving from ±38% at 0.2 Gyr to ±12% at 2 Gyr. K-dwarfs have asymmetric posteriors due to stalled spin-down. High-mass K-dwarfs (5000 K) older than 1.5 Gyr give the most precise ages, limited by spin-down rate changes, the absolute age scale, and the slow sequence width. An open-source implementation is available online at github.com/lgbouma/gyro-interp
2.10 SSEBAGGALA CHRIZESTOM Mbarara University of Science and Technology, Uganda DETERMINATION OF VARIABILITY PROPERTIES OF CANDIDATE PULSATING Am STARS The main goal of the study was to investigate the variability properties of candidate pulsating Am stars. Using TESS data and Eleanor software, light curves of 30 target stars were obtained. The light curves were fitted with a Fourier series to obtain Fourier transforms of the 30 target stars. By visual inspection of the light curves and Fourier transforms: 28 stars are variable and 2 are non-variable. Based on the Fourier transforms and the Q constant, of the 28 variable stars 4 stars have δ Scuti-type and 16 are γ Doradus-type pulsations. 7 stars of the 28 variables are rotational, 1 star is in a binary system. There are 2 stars out of the 4 δ Scuti with both rotational and pulsational signals. These results have increased the number of well known pulsating Am stars. The presence of pulsational signals in such stars brings a contradiction in the atomic diffusion models. This implies that pulsation needs to be accounted for in the atomic diffusion models in the attempt to explain the origin of chemical peculiarities in Am stars. The rotational variables are moderate to slow rotators and since their values of v sin i are known, their rotational profiles are complete.
2.11 Tara Fetherolf CSU San Marcos/UC Riverside TESS Stellar Variability Catalog (TESS-SVC) We present the TESS Stellar Variability Catalog (TESS-SVC), which includes ~84,000 stars that exhibit significant photometric variability on timescales of 0.01-13 days. The TESS-SVC includes a broad range of periodic variable stars (rotation, pulsation, eclipsing binaries, etc.) that were selected based on a photometric periodogram analysis of their 2-min cadence light curves. The TESS-SVC is now available as a HLSP on MAST that includes tabulated information about the periodic variability measured and a summary figure for each star that shows the resultant periodogram and best-fit curve to the stellar variability. The catalog will continue to be updated as new TESS data becomes available, and it will later include stars that exhibit photometric variability on timescales longer than 13 days. I will discuss the characteristics of the stars in the TESS-SVC and early science results that have utilized the catalog. Overall, the variability catalog aids 1) studying the characteristics of periodic variable stars; 2) understanding interactions between host star variability and planetary atmospheres; and 3) identifying exoplanets that are actually false positives caused by stellar variability.
2.12 Eric Gaidos University of Hawai'i at Mānoa A TESS Tale of a Telling T Tauri Star Occlusion of the central star by circumstellar dust and gas can be a powerful probe of the structure, dynamics, and composition of inner protoplanetary (T Tauri) disks that are unresolved by interferometry and adaptive optics imaging. The TESS survey permits identification of such ``dipper" stars over the entire sky, and repeated visits allow us to look for variation in behavior and plan parallel observations with other telescopes. We describe multi-epoch TESS photometry of the 4-10 Myr-old quasi-periodic dipper star EP Chamaeleontis (RECX-11) which lies close to the mission's southern continuous viewing zone. Studies of this system promise to advance our understanding of disk dissipation and lifetime; despite its age and spectral indications of disk evolution, its spectral energy distribution indicates a continuous disk, with no gaps or any cavity larger than the dust sublimation radius. This is in contrast to other members of the cluster which lack detectable disks or have inner cavities, and conflicts with models of disk dissipation by photoevaporation. We describe a multi-wavelength campaign that observed EP Cha in parallel with TESS to constrain inner disk geometry, and a future proposed campaign with HST in 2025.
2.13 Allison Youngblood NASA Goddard Space Flight Center Uncovering connections between optical and near-ultraviolet M dwarf flares with TESS and Swift Near-ultraviolet (NUV) stellar flares can drive photochemistry in the atmospheres of and harm any surface life on the exoplanets they host. We analyzed an extensive dataset of NUV and optical flares from young and old M dwarfs observed simultaneously with the Transiting Exoplanet Survey Satellite (TESS) and the Neil Gehrels Swift Observatory with supporting data from K2 and the Hubble Space Telescope. In total, we observed 213 NUV flares from 24 nearby M dwarfs, with ∼27% of them having detected optical counterparts, and found that all optical flares had NUV counterparts. We explore the energy fractionation of flares between the two bandpasses and find a slight decrease in the optical/NUV ratio with increasing NUV energy, a trend in agreement with prior investigations on more energetic G-K stellar flares. We present an empirical relationship between NUV and optical flare energies and compare to predictions from radiative-hydrodynamic and blackbody models. We find that within error bars, the flare frequency distributions (FFDs) of both NUV and optical flares across all M dwarf subtypes exhibit comparable slopes.
2.14 Lauren Doyle University of Warwick The Puzzling Story of Flare Inactive Ultra Fast Rotating M dwarfs Rapidly rotating stars are expected to produce increased levels of activity which is strongly related to their dynamo mechanism. Additionally, activity is observed to be saturated in rapid rotators with a decline in activity as a function of rotation. We have identified a group of low mass ultra-fast rotating (UFR) stars which have rotation periods less than 0.3 days and show low levels of flaring activity in their TESS light curves. We do not find any evidence that the lack of activity is related to age or rotational velocities and conclude it is most likely to be a result of the magnetic field strength/ configurations of the star. We present further analysis of 10 UFRs using TESS data, VLT/FORS2 spectropolarimetric observations and Swift X-ray observations. We compare flare rates between the TESS Cycle light curves, investigating any long-term variability and use the VLT/FORS2 spectropolarimetric data to determine an estimate on the magnetic field strength. Finally, we use the Swift X-ray observations to provide bolometric luminosity measurements and compare these to their rotation periods. Overall, this combination of data will allow us to uncover the nature of these UFRs and explain their lack of flaring activity.
2.15 Tobin Wainer University of Washington Searching for Stellar Activity Cycles using Flares: The Short and Long Timescale Activity of TIC 72272592 We examine 4 years of Kepler 30-min data, and 5 Sectors of TESS 2-min data for the dM3 star KIC 8507979/TIC-272272592. This rapidly rotating (P=1.2 day) star has previously been identified as flare active, with a possible long-term decline in its flare output. Such slow changes in surface magnetic activity are potential indicators of Solar-like activity cycles. We find that KIC 8507979 shows both short and long timescale variations in its flare activity that are larger than expected from the power-law flare occurrence distribution. Only a handful of stars have been subjected to such long baseline point-in-time flare studies. We believe this is powerful new method for measuring the months-to-years changes in surface magnetic activity, and to provide important constraints on activity cycles and dynamo models for low mass stars.
2.16 Andrew Tran University of Georgia Stellar flares of nearby young moving group (NYMG) members from TESS High-cadence optical photometric data obtained by the Transiting Exoplanet Survey Satellite (TESS) offer valuable insights into astrophysical phenomena occurring in young stars, such as stellar flares and rotation-related characteristics. We employ detrended light curves from the TESS Science Office Quick-Look Pipeline (QLP) for 560 members of young, nearby moving groups (10-150 Myr) to systematically identify stellar flares across 2100 unique QLP light curves, from Cycles 1-5 of the TESS mission. Our initial identification of flare candidates involves utilizing the AltaiPony flare package. We subsequently apply a 4th-order polynomial function to fit flare amplitudes, durations, and local continuum background level parameters for each candidate. We investigate the behavior of flare energies with respect to stellar age and mass, based on moving group membership.
2.17 Nathan Whitsett Washington University The search for induced stellar flares using TESS The detection of exoplanetary magnetic fields is an essential goal for the continued characterization and contextualization of exoplanets. In particular, an orbiting exoplanet with a magnetosphere can induce flares on its host via magnetic reconnection. We conduct a comprehensive search for induced flares in multi-cadence TESS data in the first five years of the mission, using Bayesian evidence to vet underresolved flare candidates. Specifically, we estimate the flare frequency distribution by cataloging flares from low-mass M dwarfs with confirmed or candidate planets. We discuss candidate targets potentially manifesting star-planet interactions based on elevated flaring activity correlated with arguments of periastron and Alfven-surface crossings. Continued long-term monitoring of flaring stars by TESS and the upcoming ULTRASAT mission will yield complementary tests for the accumulating evidence for the existence of planetary magnetospheres based on radio observations of the Low-Frequency Array (LOFAR) and UV observations of the Hubble Space Telescope (HST).
2.18 Kai Ikuta The University of Tokyo Starspot mapping and multiwavelength variability for a young solar-type star Recent simultaneous multiwavelength observations by the TESS, Seimei telescope, and NICER have provided evidence for stellar prominence eruptions associated with superflares on a young solar-type star EK Draconis (EK Dra) (Namekata et al. 2024). Such superflares are suggested to have been caused by large spots near the limb from the concurrent result of the Doppler Imaging at the Bernard Lyot telescope (Namekata et al., in preparation). Thus, to investigate the relation between spot locations from the optical photometry and occurrence of superflares, we perform starspot mapping for the TESS light curve of EK Dra. We also analyze the rotational variability for the TESS light curve, H$\alpha$ spectrum, and X-ray data. As a result, we find that (i) some spots are deduced to be near the limb when superflares occurred, (ii) spot locations are consistent with those obtained from the Doppler Imaging except for a polar spot, and (iii) the H$\alpha$ spectrum produced around spots exhibits clear periodicity with respect to the TESS light curve, however, the X-ray data does not show such association probably because of multiple spots on the surface and the extended spatial structure of coronal active regions (Ikuta et al., in preparation).
2.19 Zachary Lane University of Canterbury Photometric and spectroscopic time-series analysis of SN2019vxm We present the optical to UV lightcurve and spectral timeseries of SN2019vxm, which we classify as a type IIn super luminous supernova (SLSN-IIn). Combining the high-cadence TESS observations of the rise of SN2019vxm, Swift UV photometry, and ground-based optical observations, we test a range of models for the rise of type II supernovae, and search for evidence of a shock breakout. Combining the photometry with a spectroscopic time series observed from -14 to 100 days relative to peak brightness, we observe evidence of CSM interaction in the ejecta. The synthesis of the high-cadence TESS lightcurve of the rise, broad wavelength coverage, and spectroscopic time series allows us to build a comprehensive picture of the progenitor and evolution of this SLSN-IIn.
4.01 Nora Takacs Konkoly Observatory Shape and rotation modelling of asteroids based on multi-directional TESS measurements Using multi-directional measurements from the TESS, we aim to determine the approximate shape and rotation axis orientation of asteroids in the main belt. As a benchmark study, we selected 43 minor planets based on three criteria: each must have observations in at least three separate TESS sectors, an apparent magnitude of <= 17, and a corresponding solution in the DAMIT (Database of Asteroid Models from Inversion Techniques) database. Due to the limited number of observations per target, we apply a low degree-of-freedom, simple shape model of a triaxial ellipsoid, but consider different scattering laws, taking into account the actual illumination geometry obtained from relative positions of the observer and a possible pole solution. The resulting best-fit spin axis orientations show good agreement with the DAMIT solutions. We will use this technique to obtain shape and spin axis solutions for ten thousands of asteroids observed with TESS.
4.02 Andras Pal Konkoly Observatory Towards a homogeneous asteroid photometric database by TESS In this poster we exhibit the data processing steps related to a photometric database of asteroids as observed by TESS. Up to Sector 55, more than 750,000 known asteroids have crossed the field-of-view of the instrument, providing ~2.4 visits per object on average. While the majority of these ~1.8 million individual light curve segments are indeed too faint for a precise photometry, specially crafted procedures applied both on the images and the extracted flux values yield reliable rotational characteristics of asteroids up to the order of a hundred thousand. Information on spin axis orientation is also available for an enormous amount of minor planets due to the high variability of observational geometries for objects with repeated visits spanned through multiple years. In addition, the lessons learned for moving object photometry aid the analysis of stationary sources.
5.01 Lauren Herrington Massachusetts Institute of Technology Estimating Rotation Rates of the Brightest Solar-type Stars with TESS Magnetic features rotating across the surface of a star create photometric variations on timescales of days to weeks, enabling direct measurement of a star’s rotation rate. These variations are low amplitude, making them difficult to detect from the ground, but with TESS, rotational modulation can be observed in hundreds of bright stars. Here we present a catalog of estimated rotation rates and photometric amplitudes for over 200 of the brightest solar-type stars. Because automated searches are subject to spurious detections regardless of periodogram power, we constrained our estimations via direct visual inspection. The resulting list has a very low false positive rate, and will be used to inform target selection for the Copernicus Constellation, a proposed satellite constellation designed to discover Earth-like exoplanets transiting nearby Sun-like stars. Copernicus’ critical Phase 1 mission relies on targeting only the fastest-rotating stars, in order to resolve asteroseismic mode splits and identify stars with inclinations favorable to exoplanetary transits. This TESS-based rotation catalog will allow us to optimize Copernicus’ asteroseismic search, extending the amount of mission time available for the Phase 2 transit search.
5.02 Petr Kabath Astronomical Institute of the Czech Academy of Sciences PLATOSpec, support for the space missions We will present the PLATOSpec project with its recent results. PLATOSpec is a new spectrograph installed at E152 telescope at La Silla, Chile. Main goal is the follow-up observation of candidates from space missions such as TESS and later PLATO. PLATOSpec contributes to various research topics, such as stellar variability, characterization of host stars with exoplanets and obliquity measurements. Furthermore, we plan to use PLATOSpec as test bench for a new ultraprecise instrument for the terrestrial planet candidates from PLATO. Here, we will present our concept of such instrument.
6.01 Nikoo Hosseininezhad CUNY Queens College TESS CROWDSAP Errors from White Dwarf Observations CROWDSAP is a metric within the TESS analysis pipeline, the fraction of light in the aperture estimated to come from the targeted star. This study specifically targets the TESS light curves of White Dwarfs observed across various sectors, with the goal of evaluating the uncertainties associated with CROWDSAP values. White Dwarfs, characterized by their stable luminosity, theoretically should display uniform flux readings across observational sectors. However, TESS's observed flux variations offer a unique lens through which to assess CROWDSAP's precision. Identifying the extent of these flux inconsistencies allows us to explore the potential impact of CROWDSAP inaccuracies on critical measurements such as transit depth and signal amplitude.
6.02 Keaton Bell CUNY Queens College Identifying the source of variability with TESS-Localize TESS has a huge plate scale of 21”/pixel. As a result, most TESS light curves represent a blend of multiple sources. If you detect variability in a TESS light curve, how do you know which source is variable? One should certainly not assume that it is the star around which the light curve was extracted! Answering this critical question requires the TESS pixel data to be analyzed, in addition to the light curve. Never fear---the Python package TESS-Localize is designed to help. This poster demonstrates the importance of confirming the source of detected variability in the TESS data, shows how to perform this analysis with TESS-Localize, and describes the multiple considerations necessary to reliably interpret the code output.
6.03 Joseph Vincent Lupo MIT Modeling and Removal of Scattered Light in TESS Full Frame Images Using Generative AI Scattered light from the Earth and Moon can significantly impact the background levels in TESS full frame images (FFIs), hindering the search for transiting exoplanets and other astronomical phenomena. While scattered light is often corrected at the light curve level, we present a novel approach to model and remove scattered light at the image level using deep learning. We have developed a conditional diffusion model that accurately captures the scattered light patterns in FFIs probabilistically, using only the angles and distances of the Earth and Moon with respect to the TESS cameras. The model learns the complex, dynamic patterns of scattered light and produces corrected FFIs along with uncertainties. By removing scattered light at the image level, we can enable improved photometry and planet searches in scattered light-affected regions of the FFIs. We demonstrate the performance of our model on all TESS sectors. This deep learning approach opens up new avenues for scattered light and systematics correction in present and future space-based surveys.
6.04 Joseph Twicken SETI Institute/NASA Ames Research Center Joint Difference Image Centroiding to Better Establish Transit Source Location Difference image centroid offset analysis has proven to be a powerful diagnostic tool for validation of Threshold Crossing Events (TCEs) in the Kepler and TESS pipelines. Spatial information available at the pixel level is exploited to estimate the location of the transit source. For TESS targets observed in multiple sectors, images representing the difference between mean out-of-transit and in-transit flux are typically constructed for each sector. Offsets between the per-sector centroids and target star position are robustly averaged to estimate the transit source location with respect to the target. The traditional approach is deficient, however, for TCEs often associated with small planets. Centroiding individual difference images does not take advantage of the increased SNR achievable with additional data, and the process breaks down when SNR is low in individual sectors. We propose a new approach to difference image centroiding whereby all available difference images are centroided jointly based on CCD-specific Pixel Response Functions. We perform a Monte Carlo assessment of the uncertainties in the resulting centroid offsets and provide examples for a sample of confirmed TESS planets and background binary false positives.
6.05 Eric Feigelson Penn State University DIAmante TESS AutoRegressive Planet Search (DTARPS): Overview and Methodology The AutoRegressive Planet Search (ARPS) project develops a statistical methodology for transiting planet detection. It starts with ARIMA, the econometric modeling procedure for stochastic time series that fits both trends and autocorrelation. A novel periodogram, the Transit Comb Filter (TCF), is applied to the ARIMA residuals. TCF demonstrably has better statistical properties and higher sensitivity to smaller planets than the Box-Least Squares periodogram. A decision tree classifier, trained towards injected planets and away from eclipsing binaries, is applied to ARPS features. This procedure was applied to 150K stars in the Kepler 4-year, resulting in the identification of 97 (sub)-Earth candidate exoplanets. For the TESS Year 1 survey (DTARPS-S), the analysis begins with 0.9M pre-processed light curves from the DIAmante project. 7,743 stars pass the classifier threshold with excellent True Positive recall and False Positive rejection, and excellent completeness in the planetary Radius-Period diagram. The classifier-selected sample is then subjected to a suite of conservative vetting procedures, giving a high-purity ARPS candidate catalog of 642 stars at high-Galactic latitude and 310 stars near the Galactic Plane.
6.06 Elizabeth Melton Rose-Hulman Institute of Technology DIAmante TESS AutoRegressive Planet Search (DTARPS): Results from the DTARPS-S Catalog The AutoRegressive Planet Search method was applied to DIAmante extracted light curves from TESS Year 1 and Year 2 Full Frame Images identifying a high purity set of DTARPS candidates. Several lines of evidence, including limited reconnaissance spectroscopy and stellar youth, indicate that at least half are true planets rather than False Positives. Approximately half of the DTARPS candidates are hot Neptunes, populating the ‘Neptune desert’ found in Kepler planet samples; careful analysis indicates that this overabundance of candidates is a characteristic of the TESS data. Several newly confirmed TESS planets in the ‘Neptune desert’ have indicated that it may be a ‘Neptune savannah’. Recent studies indicate a higher prevalence of hot Neptunes for young stellar hosts which agrees with the median ages of the TESS and the Kepler fields. DTARPS methodology is sufficiently well-characterized at each step that preliminary planet occurrence rates can be estimated. Except for the increase in hot Neptunes, DTARPS-S planet occurrence rates are consistent with Kepler rates. DTARPS methodology provides highly reliable catalogs of exoplanet candidates that can improve both our current understanding and be applied to future missions.
6.07 Jon Jenkins NASA Ames Research Center TIC 271971130.02 is Unlikely to be a Transiting Planet The transiting planet, TOI-715 b, was discovered in the habitable zone of its host M4 star with an orbital period of 19.29 days, an instellation of 0.67 S⊕, and a radius of 1.55 R⊕, placing it within the M-dwarf radius valley (Dransfield+2024). We also identified a second candidate planet, TIC 271971130.02, at an SNR of 13.8 σ, an orbital period of 25.6 days and a radius of 1.07 R⊕ using a transit search algorithm coupled with a smoothing prefilter. If confirmed, this would be the smallest habitable zone planet to date. However, the TESS Science Processing Operations Center (SPOC) did not detect a signature at 25.6 days, and constrained the SNR to ≤5.5 σ. The SPOC recently conducted a transit search over sectors 1-69, recovering the signature of TOI-715 b at an SNR of 21.6 σ, as expected given the additional transits, but failed again to detect a signal at 25.6 days, constraining the SNR to ≤5.5 σ. Since the SNR of the putative signal failed to grow as expected with the additional data, TIC 271971130.02 is unlikely to be a genuine transiting planet signal. We discuss how the use of a smoothing prefilter can inflate the apparent SNR when Box Least-Squares or Transit Least-Squares is used for transit searches.
6.08 Vincent Vanlaer KU Leuven From light curves to stars: past, current, and future asteroseismic modelling techniques Stellar evolution presents a complicated challenge, with gaps in our knowledge affecting many aspects of astronomy, such as exoplanet characterization and galactic chemical evolution. Luckily, space telescopes like Kepler and TESS give us light curves for millions of objects. By studying the pulsating stars among these, we are able to use the precision of this data to probe the internal structure and evolution of stars in great detail, across all masses and evolutionary stages. However, just having access to these large datasets and their observational diagnostics is not sufficient: the modelling techniques and the stellar models themselves need to be sufficiently advanced and efficient to exploit the data maximally. In this talk I will first review the asteroseismic modelling techniques for intermediate- and high-mass stars that have been developed the past few years. Particular attention will be paid to inversion methods as an improvement of forward modelling techniques. We highlight the challenges of such methods for stars with faster rotation and slower oscillations than those of sun-like stars for which linear inversion methods work well. We end with a plan towards non-linear inversion methods for TESS pulsators.
6.09 Isabel Colman American Museum of Natural History Methods for the detection of stellar rotation in TESS and results from the Prime mission The TESS mission has given stellar astrophysicists the opportunity to search and catalog the whole sky. This is proving to be vital in studies of stellar rotation: many recent advances have been spurred by extensive analysis of space-based data and the development of large rotation period catalogs. This effort requires accurate measurement and reliable automation. We present the results of a dedicated study to detect short (13 days and under) rotation periods in individual TESS sectors. Our pipeline uses the Lomb-Scargle periodogram and autocorrelation function as tools for period detection; we then use these data to describe each sector in feature space, and measurements are vetted by a two-stage random forest classifier procedure. We searched over 430,000 individual TESS sectors to produce a high-fidelity catalog of short rotation periods for 10,909 main sequence FGKM stars in the TESS prime mission. We also present a thorough methodological study, providing insight into the application of machine learning techniques to the analysis of stellar variability in TESS data. Finally, we discuss ongoing work to extend our search for stellar rotation to longer periods in the TESS continuous viewing zones.
6.10 Stephanie Striegel SETI Institute/NASA Ames Research Center The TESS Science Processing Operations Center The TESS Science Processing Operations Center (SPOC) at NASA Ames Research Center is the official pipeline of record for the TESS mission. The SPOC processes TESS full-frame images (FFIs) which, in Extended Mission 2, are taken at a 200-second cadence, as well as 2-minute “postage stamps” of 13,000-20,000 targets and 20-second “postage stamps” of 1,000-2,000 targets. FFIs are received and processed weekly while the 2-minute and 20-second data are received bi-weekly and processed at the end of each sector. The SPOC generates mission light curves for specified target stars and calibrated pixels so that the community may create their own light curves. These data products are delivered to the Payload Operations Center at MIT and subsequently archived to the Mikulski Archive for Space Telescopes (MAST) for public access. The SPOC also delivers high-level science products which include target pixel and light curve files for up to 160,000 targets selected from FFIs. These products include calibrated target pixels, simple aperture photometry flux time series, and systematic error-corrected flux time series. To release data more efficiently to the community, the SPOC is implementing direct to MAST delivery of all SPOC data products.
6.11 Lauren Doyle University of Warwick The TESS-SPOC FFI Target Sample Explored with Gaia The TESS mission's Full Frame Image (FFI) light curves, comprising of over 2.8 million stars, are pivotal for precise times series photometry in transiting exoplanet studies. Produced by the TESS Science Processing Operations Centre (SPOC), this set of light curves is an extremely valuable resource for the discovery of transiting exoplanets and other stellar science. Due to the sample selection, this set of light curves does not constitute a magnitude limited sample. Addressing sample selection effects, we utilise Gaia DR2 and DR3 to analyse the properties of the TESS-SPOC FFI targets from Sectors 1 – 55. By cross-matching the TESS-SPOC FFI Targets with 16.7 million Gaia targets brighter than G=14, we investigate stellar properties including magnitude, parallax, radius, temperature and binarity. Furthermore, we reveal the TESS-SPOC FFI sample in the HRD for the first time and allow for the sample to be adapted for statistical studies. For each TESS-SPOC FFI Target we calculate the radius detection limit of two transit events which could be detected around each target. We also create a comprehensive main sequence TESS-SPOC FFI Target sample which can be utilised in future studies.
6.12 Bisi Bernard Ogunwale Ariel University, Israel Towards a new catalog of variable point sources from TESS FFIs The TESS full-frame images (FFIs) have a great potential for providing high-quality data for studying galactic and extragalactic transients in addition to the detection of transiting planets and binaries. However, FFIs are subject to spatial and temporal systematic errors originating from both the instru, ment and external sources, such as scattered light from the earth and the moon. Although a variety of software solutions have been developed to address this issue, the majority of them require the user to provide positional information prior to producing light curves from FFIs. The purpose of our study is to compile a catalog of all variable sources, including transient and moving objects, observed in the FFIs. Each lightcurve file will contain metadata with statistical and descriptive feature information, which can be used to search for astrophysical phenomena of particular interest. The catalog will serve as a reference for scientists to access high-level scientific data without having to process the FFIs from scratch

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