Dr. Rabus, Markus

Large-scale exoplanet surveys like the Transiting Exoplanet Survey Satellite (TESS) mission are powerful tools for discovering large numbers of exoplanet candidates. Single-transit events are commonplace within the resulting candidate list due to the unavoidable limitation of the observing baseline. These single-transit planets often remain unverified due to their unknown orbital periods and consequent difficulty in scheduling follow-up observations. In some cases, radial velocity (RV) follow up can constrain the period enough to enable a future targeted transit detection. We present the confirmation of one such planet: TOI-2010 b. Nearly three years of RV coverage determined the period to a level where a broad window search could be undertaken with the Near-Earth Object Surveillance Satellite, detecting an additional transit. An additional detection in a much later TESS sector solidified our final parameter estimation. We find TOI-2010 b to be a Jovian planet (MP = 1.29 MJup, RP = 1.05 RJup) on a mildly eccentric orbit (e = 0.21) with a period of P = 141.83403 days. Assuming a simple model with no albedo and perfect heat redistribution, the equilibrium temperature ranges from about 360 to 450 K from apastron to periastron. Its wide orbit and bright host star (V = 9.85) make TOI-2010 b a valuable test bed for future lowinsolation atmospheric analysis.

We present and confirm TOI-1751 b, a transiting sub-Neptune orbiting a slightly evolved, solar-type, metal-poor star (Teff = 5996 ± 110 K, log(g)=4.2 + 0.1, V = 9.3 mag, [Fe/H] = −0.40 ± 0.06 dex) every 37.47 days. We use TESS photometry to measure a planet radius of 2.77-0.07+0.15 R. We also use both Keck/HIRES and APF/Levy radial velocities (RV) to derive a planet mass of 14.5-3.14+3.15M, and thus a planet density of 3.6 ± 0.9 g cm−3. There is also a long-period (∼400 days) signal that is observed in only the Keck/HIRES data. We conclude that this long-period signal is not planetary in nature and is likely due to the window function of the Keck/HIRES observations. This highlights the role of complementary observations from multiple observatories to identify and exclude aliases in RV data. Finally, we investigate the potential compositions of this planet, including rocky and water-rich solutions, as well as theoretical irradiated ocean models. TOI-1751 b is a warm sub-Neptune with an equilibrium temperature of ∼820 K. As TOI-1751 is a metal-poor star, TOI-1751 b may have formed in a water-enriched formation environment. We thus favor a volatile-rich interior composition for this planet.

Astronomers do not have a complete picture of the effects of wide-binary companions (semimajor axes greater than 100 au) on the formation and evolution of exoplanets. We investigate these effects using new data from Gaia Early Data Release 3 and the Transiting Exoplanet Survey Satellite mission to characterize wide-binary systems with transiting exoplanets. We identify a sample of 67 systems of transiting exoplanet candidates (with well-determined, edge-on orbital inclinations) that reside in wide visual binary systems. We derive limits on orbital parameters for the wide-binary systems and measure the minimum difference in orbital inclination between the binary and planet orbits. We determine that there is statistically significant difference in the inclination distribution of wide-binary systems with transiting planets compared to a control sample, with the probability that the two distributions are the same being 0.0037. This implies that there is an overabundance of planets in binary systems whose orbits are aligned with those of the binary. The overabundance of aligned systems appears to primarily have semimajor axes less than 700 au. We investigate some effects that could cause the alignment and conclude that a torque caused by a misaligned binary companion on the protoplanetary disk is the most promising explanation.

We report the discovery of two short-period massive giant planets from NASA's Transiting Exoplanet Survey Satellite (TESS). Both systems, TOI-558 (TIC 207110080) and TOI-559 (TIC 209459275), were identified from the 30 minute cadence full-frame images and confirmed using ground-based photometric and spectroscopic follow-up observations from TESS's follow-up observing program working group. We find that TOI-558 b, which transits an F-dwarf (M* = ${1.349}_{-0.065}^{+0.064}$ M⊙, R* = ${1.496}_{-0.040}^{+0.042}$ R⊙, Teff = ${6466}_{-93}^{+95}$ K, age ${1.79}_{-0.73}^{+0.91}$ Gyr) with an orbital period of 14.574 days, has a mass of 3.61 ± 0.15 MJ, a radius of ${1.086}_{-0.038}^{+0.041}$ RJ, and an eccentric (e = ${0.300}_{-0.020}^{+0.022}$) orbit. TOI-559 b transits a G dwarf (M* = 1.026 ± 0.057 M⊙, R* = ${1.233}_{-0.026}^{+0.028}$ R⊙, Teff = ${5925}_{-76}^{+85}$ K, age ${6.8}_{-2.0}^{+2.5}$ Gyr) in an eccentric (e = 0.151 ± 0.011) 6.984 days orbit with a mass of ${6.01}_{-0.23}^{+0.24}$ MJ and a radius of ${1.091}_{-0.025}^{+0.028}$ RJ. Our spectroscopic follow up also reveals a long-term radial velocity trend for TOI-559, indicating a long-period companion. The statistically significant orbital eccentricity measured for each system suggests that these planets migrated to their current location through dynamical interactions. Interestingly, both planets are also massive (>3 MJ), adding to the population of massive giant planets identified by TESS. Prompted by these new detections of high-mass planets, we analyzed the known mass distribution of hot and warm Jupiters but find no significant evidence for multiple populations. TESS should provide a near magnitude-limited sample of transiting hot Jupiters, allowing for future detailed population studies.