ORCID Profile
0000-0002-2135-9018
Current Organisation
Massachusetts Institute of Technology
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Publisher: American Astronomical Society
Date: 05-01-2023
Abstract: Convergent disk migration has long been suspected to be responsible for forming planetary systems with a chain of mean-motion resonances (MMRs). Dynamical evolution over time could disrupt the delicate resonant configuration. We present TOI-1136, a 700 ± 150 Myr old G star hosting at least six transiting planets between ∼2 and 5 R ⊕ . The orbital period ratios deviate from exact commensurability by only 10 −4 , smaller than the ∼10 −2 deviations seen in typical Kepler near-resonant systems. A transit-timing analysis measured the masses of the planets (3–8 M ⊕ ) and demonstrated that the planets in TOI-1136 are in true resonances with librating resonant angles. Based on a Rossiter–McLaughlin measurement of planet d, the star’s rotation appears to be aligned with the planetary orbital planes. The well-aligned planetary system and the lack of a detected binary companion together suggest that TOI-1136's resonant chain formed in an isolated, quiescent disk with no stellar flyby, disk warp, or significant axial asymmetry. With period ratios near 3:2, 2:1, 3:2, 7:5, and 3:2, TOI-1136 is the first known resonant chain involving a second-order MMR (7:5) between two first-order MMRs. The formation of the delicate 7:5 resonance places strong constraints on the system’s migration history. Short-scale (starting from ∼0.1 au) Type-I migration with an inner disk edge is most consistent with the formation of TOI-1136. A low disk surface density (Σ 1 au ≲ 10 3 g cm −2 lower than the minimum-mass solar nebula) and the resultant slower migration rate likely facilitated the formation of the 7:5 second-order MMR.
Publisher: IOP Publishing
Date: 09-2021
Publisher: American Astronomical Society
Date: 14-10-2021
Publisher: American Astronomical Society
Date: 06-2021
Publisher: Oxford University Press (OUP)
Date: 27-03-2023
Abstract: Transiting exoplanets orbiting young nearby stars are ideal laboratories for testing theories of planet formation and evolution. However, to date only a handful of stars with age & Gyr have been found to host transiting exoplanets. Here we present the discovery and validation of a sub-Neptune around HD 18599 , a young (300 Myr), nearby (d = 40 pc) K star. We validate the transiting planet candidate as a bona fide planet using data from the TESS , Spitzer , and Gaia missions, ground-based photometry from IRSF , LCO , PEST , and NGTS , speckle imaging from Gemini, and spectroscopy from CHIRON , NRES , FEROS , and Minerva-Australis . The planet has an orbital period of 4.13 d , and a radius of 2.7 R⊕ . The RV data yields a 3-σ mass upper limit of 30.5 M⊕ which is explained by either a massive companion or the large observed jitter typical for a young star. The brightness of the host star (V∼9 mag) makes it conducive to detailed characterization via Doppler mass measurement which will provide a rare view into the interior structure of young planets.
Publisher: American Astronomical Society
Date: 25-03-2021
Abstract: We present the discovery and characterization of five hot and warm Jupiters—TOI-628 b (TIC 281408474 HD 288842), TOI-640 b (TIC 147977348), TOI-1333 b (TIC 395171208, BD+47 3521A), TOI-1478 b (TIC 409794137), and TOI-1601 b (TIC 139375960)—based on data from NASA’s Transiting Exoplanet Survey Satellite (TESS). The five planets were identified from the full-frame images and were confirmed through a series of photometric and spectroscopic follow-up observations by the TESS Follow-up Observing Program Working Group. The planets are all Jovian size ( R P = 1.01–1.77 R J ) and have masses that range from 0.85 to 6.33 M J . The host stars of these systems have F and G spectral types (5595 ≤ T eff ≤ 6460 K) and are all relatively bright (9.5 V 10.8, 8.2 K 9.3), making them well suited for future detailed characterization efforts. Three of the systems in our s le (TOI-640 b, TOI-1333 b, and TOI-1601 b) orbit subgiant host stars ( g 4.1). TOI-640 b is one of only three known hot Jupiters to have a highly inflated radius ( R P 1.7 R J , possibly a result of its host star’s evolution) and resides on an orbit with a period longer than 5 days. TOI-628 b is the most massive, hot Jupiter discovered to date by TESS with a measured mass of M J and a statistically significant, nonzero orbital eccentricity of e = . This planet would not have had enough time to circularize through tidal forces from our analysis, suggesting that it might be remnant eccentricity from its migration. The longest-period planet in this s le, TOI-1478 b ( P = 10.18 days), is a warm Jupiter in a circular orbit around a near-solar analog. NASA’s TESS mission is continuing to increase the s le of well-characterized hot and warm Jupiters, complementing its primary mission goals.
Publisher: American Astronomical Society
Date: 29-10-2021
Publisher: American Astronomical Society
Date: 26-08-2020
Location: United States of America
No related grants have been discovered for Katharine Hesse.