collaborators

10 papers

astro-ph.EP2026

POSEIDON III: The Aligned Orbit of the Hot Neptune Around the Hot Star WASP-195

Juan I. Espinoza-Retamal, Joshua N. Winn, Rafael Brahm +33

Stellar obliquities provide important clues as to the formation and migration histories of planetary systems, but measurements remain scarce for Neptune-mass planets, especially th…

astro-ph.EP2026

Spin-Orbit Alignment of Two Neptune-size Planets Younger than 500 Myr: TOI-560 b and TOI-5082 b

Elina Y. Zhang, Fei Dai, Andrew W. Howard +25

Stellar obliquity measurements provide a direct probe of planetary system dynamics, but remain sparse for Neptune-size planets, particularly at young ages. We present Rossiter-McLa…

astro-ph.EP2026

TOI-4495: A Pair of Aligned, Near-Resonant Sub-Neptunes that Likely Experienced Overstable Migration

Mu-Tian Wang, Fei Dai, Hui-Gen Liu +24

We report the discovery of a sub-Neptune and a Neptune-like planet (, ) orbiting the F-type star TOI-449…

astro-ph.SR2025

A Test of Substellar Evolutionary Models with High-Precision Ages from Asteroseismology and Gyrochronology for the Benchmark System HR 7672AB

Yaguang Li, Michael C. Liu, Trent J. Dupuy +35

We present high-precision measurements for HR~7672AB, composed of a Sun-like (G0V) star and an L~dwarf companion. Three nights of precise (70 cm/s) radial velocity (RV) asteroseism…

astro-ph.EP2025

The KPF SURFS-UP Survey I: Transmission Spectroscopy of WASP-76 b

Aaron Householder, Fei Dai, Aurora Kesseli +25

We introduce the KPF SURFS-UP (Spectroscopy of the Upper-atmospheres and ReFractory Species in Ultra-hot Planets) Survey, a high-resolution survey to investigate the atmospheric co…

astro-ph.EP2025

TOI-880 is an Aligned, Coplanar, Multi-planet System

Elina Y. Zhang, Huan-Yu Teng, Fei Dai +22

Although many cases of stellar spin-orbit misalignment are known, it is usually unclear whether a single planet's orbit was tilted or if the entire protoplanetary disk was misalign…

astro-ph.EP2025

Stellar Obliquity of the Ultra-Short-Period Planet System HD 93963

Huan-Yu Teng, Fei Dai, Andrew W. Howard +24

We report an observation of the Rossiter-McLaughlin (RM) effect of the transiting planet HD 93963 Ac, a mini-Neptune planet orbiting a G0-type star with an orbital period of $P_{\r…

astro-ph.EP2025

Doppler Shifted Transient Sodium Detection by KECK/HIRES

Athira Unni, Apurva V. Oza, H. Jens Hoeijmakers +12

We carried out the first high-resolution transit observations of the exoplanet WASP-49 Ab with Keck/HIRES. Upon custom wavelength calibration we achieve a Doppler RV precision of $…

astro-ph.SR2025

K-dwarf Radius Inflation and a 10-Gyr Spin-down Clock Unveiled through Asteroseismology of HD 219134 from the Keck Planet Finder

Yaguang Li, Daniel Huber, J. M. Joel Ong +26

We present the first asteroseismic analysis of the K3\,V planet host HD~219134, based on four consecutive nights of radial velocities collected with the Keck Planet Finder. We appl…

astro-ph.EP2025

TOI-6324b: An Earth-Mass Ultra-Short-Period Planet Transiting a Nearby M Dwarf

Rena A. Lee, Fei Dai, Andrew W. Howard +71

We report the confirmation of TOI-6324 b, an Earth-sized (1.059 0.041 R) ultra-short-period (USP) planet orbiting a nearby (20 pc) M dwarf. Using the newly com…