Search Publications
Characterization of a Set of Small Planets with TESS and CHEOPS and an Analysis of Photometric Performance
Torres, Guillermo; Bieryla, Allyson; Stassun, Keivan G. +41 more
The radius valley carries implications for how the atmospheres of small planets form and evolve, but this feature is visible only with highly precise characterizations of many small planets. We present the characterization of nine planets and one planet candidate with both NASA TESS and ESA CHEOPS observations, which adds to the overall population…
Asteroseismology and Spectropolarimetry of the Exoplanet Host Star λ Serpentis
Li, Yaguang; Ayres, Thomas R.; Kochukhov, Oleg +31 more
The bright star λ Ser hosts a hot Neptune with a minimum mass of 13.6 M ⊕ and a 15.5 day orbit. It also appears to be a solar analog, with a mean rotation period of 25.8 days and surface differential rotation very similar to the Sun. We aim to characterize the fundamental properties of this system and constrain the evolutionary pathway …
The Panchromatic Hubble Andromeda Treasury. XX. The Disk of M31 is Thick
Bell, Eric F.; Dolphin, Andrew E.; Williams, Benjamin F. +6 more
We present a new approach to measuring the thickness of a partially face-on stellar disk, using dust geometry. In a moderately-inclined disk galaxy, the fraction of reddened stars is expected to be 50% everywhere, assuming that dust lies in a thin midplane. In a thickened disk, however, a wide range of radii project onto the line of sight. Assumin…
Deep Orbital Search for Additional Planets in the HR 8799 System
Do Ó, Clarissa R.; De Rosa, Robert J.; Macintosh, Bruce +6 more
The HR 8799 system hosts four massive planets orbiting 15 and 80 au. Studies of the system's orbital stability and its outer debris disk open the possibility of additional planets, both interior to and exterior to the known system. Reaching a sufficient sensitivity to search for interior planets is very challenging due to the combination of bright…
The TESS-Keck Survey. XVI. Mass Measurements for 12 Planets in Eight Systems
Anderson, Jay; Dattilo, Anne; Batalha, Natalie M. +45 more
With JWST's successful deployment and unexpectedly high fuel reserves, measuring the masses of sub-Neptunes transiting bright, nearby stars will soon become the bottleneck for characterizing the atmospheres of small exoplanets via transmission spectroscopy. Using a carefully curated target list and observations from more than 2 yr of APF-Levy and …
Using Photometrically Derived Properties of Young Stars to Refine TESS's Transiting Young Planet Survey Completeness
Pascucci, Ilaria; Cunha, Katia; Mamajek, Eric E. +7 more
The demographics of young exoplanets can shed light on their formation and evolution processes. Exoplanet properties are derived from the properties of their host stars. As such, it is important to accurately characterize the host stars since any systematic biases in their derivation can negatively impact the derivation of planetary properties. He…
Binary Star Evolution in Different Environments: Filamentary, Fractal, Halo, and Tidal Tail Clusters
Tang, Shih-Yun; Pang, Xiaoying; Li, Chengyuan +7 more
Using membership of 85 open clusters from previous studies based on Gaia Data Release 3 data, we identify binary candidates in the color-magnitude diagram for systems with mass ratio q > 0.4. The binary fraction is corrected for incompleteness at different distances due to the Gaia angular resolution limit. We find a decreasing binary fraction …
TOI-199 b: A Well-characterized 100 day Transiting Warm Giant Planet with TTVs Seen from Antarctica
Trifonov, Trifon; Henning, Thomas; Latham, David W. +49 more
We present the spectroscopic confirmation and precise mass measurement of the warm giant planet TOI-199 b. This planet was first identified in TESS photometry and confirmed using ground-based photometry from ASTEP in Antarctica including a full 6.5 hr long transit, PEST, Hazelwood, and LCO; space photometry from NEOSSat; and radial velocities (RVs…
JWST/NIRCam Coronagraphy of the Young Planet-hosting Debris Disk AU Microscopii
Barclay, Thomas; Young, Erick T.; Boccaletti, Anthony +20 more
High-contrast imaging of debris disk systems permits us to assess the composition and size distribution of circumstellar dust, to probe recent dynamical histories, and to directly detect and characterize embedded exoplanets. Observations of these systems in the infrared beyond 2-3 µm promise access to both extremely favorable planet contrast…
A Mini-Neptune Orbiting the Metal-poor K Dwarf BD+29 2654
Hellier, Coel; Batalha, Natalie M.; Kane, Stephen R. +48 more
We report the discovery and Doppler mass measurement of a 7.4 days 2.3 R ⊕ mini-Neptune around a metal-poor K dwarf BD+29 2654 (TOI-2018). Based on a high-resolution Keck/HIRES spectrum, the Gaia parallax, and multiwavelength photometry from the UV to the mid-infrared, we found that the host star has ${T}_{\mathrm{eff}}={4174}_{-42}^{+3…