Search Publications
Detection of Atmospheric Escape from Four Young Mini-Neptunes
Knutson, Heather A.; Ricker, George R.; Dai, Fei +5 more
We use Keck/NIRSPEC to survey a sample of of young (<1 Gyr), short-period mini-Neptunes orbiting nearby K dwarfs to measure their mass loss via the metastable helium line. We detect helium absorption from all four of the targets in our initial sample. The first detection, around TOI 560b, was announced in a previous paper. We now announce three…
Occurrence Rate of Hot Jupiters Around Early-type M Dwarfs Based on Transiting Exoplanet Survey Satellite Data
Latham, David W.; Stassun, Keivan G.; Collins, Karen A. +26 more
We present an estimate of the occurrence rate of hot Jupiters (7 R ⊕ ≤ R p ≤ 2 R J, 0.8 ≤ P b ≤ 10 days) around early-type M dwarfs based on stars observed by the Transiting Exoplanet Survey Satellite (TESS) during its primary mission. We adopt stellar parameters from the TESS Input Catalog and const…
Evidence for Hidden Nearby Companions to Hot Jupiters
Rice, Malena; Wang, Songhu; Wu, Dong-Hong
The first discovered extrasolar worlds-giant, "hot Jupiter" planets on short-period orbits-came as a surprise to solar system-centric models of planet formation, prompting the development of new theories for planetary system evolution. The near absence of observed nearby planetary companions to hot Jupiters has been widely quoted as evidence in su…
TOI-1136 is a Young, Coplanar, Aligned Planetary System in a Pristine Resonant Chain
Terentev, Ivan A.; Batalha, Natalie M.; Bieryla, Allyson +60 more
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 ⊕. Th…
TOI-5205b: A Short-period Jovian Planet Transiting a Mid-M Dwarf
Kobulnicky, Henry A.; Cochran, William D.; Mahadevan, Suvrath +27 more
We present the discovery of TOI-5205b, a transiting Jovian planet orbiting a solar metallicity M4V star, which was discovered using Transiting Exoplanet Survey Satellite photometry and then confirmed using a combination of precise radial velocities, ground-based photometry, spectra, and speckle imaging. TOI-5205b has one of the highest mass ratios…
Detailed Chemical Abundances of Stars in the Outskirts of the Tucana II Ultrafaint Dwarf Galaxy
Jerjen, Helmut; Frebel, Anna; Simon, Joshua D. +6 more
We present chemical abundances and velocities of five stars between 0.3 and 1.1 kpc from the center of the Tucana II ultrafaint dwarf galaxy (UFD) from high-resolution Magellan/MIKE spectroscopy. We find that every star is deficient in metals (-3.6 < [Fe/H] < -1.9) and in neutron-capture elements as is characteristic of UFD stars, unambiguou…
ELemental abundances of Planets and brown dwarfs Imaged around Stars (ELPIS). I. Potential Metal Enrichment of the Exoplanet AF Lep b and a Novel Retrieval Approach for Cloudy Self-luminous Atmospheres
Fortney, Jonathan J.; Carter, Aarynn L.; Skemer, Andrew +10 more
AF Lep A+b is a remarkable planetary system hosting a gas-giant planet that has the lowest dynamical mass among directly imaged exoplanets. We present an in-depth analysis of the atmospheric composition of the star and planet to probe the planet's formation pathway. Based on new high-resolution spectroscopy of AF Lep A, we measure a uniform set of…
Hubble Space Telescope Transmission Spectroscopy for the Temperate Sub-Neptune TOI-270 d: A Possible Hydrogen-rich Atmosphere Containing Water Vapor
Madhusudhan, Nikku; Mikal-Evans, Thomas; Crossfield, Ian J. M. +6 more
TOI-270 d is a temperate sub-Neptune discovered by the Transiting Exoplanet Survey Satellite (TESS) around a bright (J = 9.1 mag) M3V host star. With an approximate radius of 2 R ⊕ and equilibrium temperature of 350 K, TOI-270 d is one of the most promising small exoplanets for atmospheric characterization using transit spectroscopy. He…
Rotation Periods, Inclinations, and Obliquities of Cool Stars Hosting Directly Imaged Substellar Companions: Spin-Orbit Misalignments Are Common
Huber, Daniel; Zhou, Yifan; Tran, Quang H. +10 more
The orientation between a star's spin axis and a planet's orbital plane provides valuable information about the system's formation and dynamical history. For non-transiting planets at wide separations, true stellar obliquities are challenging to measure, but lower limits on spin-orbit orientations can be determined from the difference between the …
A Census of the Taurus Star-forming Region and Neighboring Associations with Gaia
Luhman, K. L.
I have used high-precision photometry and astrometry from the third data release of Gaia to perform a survey for members of the Taurus star-forming region and young associations in its vicinity. This work has produced a new catalog of 532 adopted members of Taurus, which has only minor changes relative to the previous catalog from Esplin & Luh…