papers

Publications (12)

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.EP2024

A Gaussian process model for stellar activity in 2-D line profile time-series

Haochuan Yu, Suzanne Aigrain, Baptiste Klein +3

Stellar active regions like spots and faculae can distort the shapes of spectral lines, inducing variations in the radial velocities that are often orders of magnitude larger than…

astro-ph.IM2021

Refractive index and extinction coefficient of vapor-deposited water ice in the UV-Vis range

Jiao He, Sharon J. M. Diamant, Siyu Wang +4

Laboratory results of the optical properties of vapor-deposited water ice, specifically the refractive index and extinction coefficient, are available mainly for a selective set of…

astro-ph.EP2025

No TiO detected in the hot Neptune-desert planet LTT-9779 b in reflected light at high spectral resolution

Sophia R. Vaughan, Jayne L. Birkby, Natasha E. Batalha +12

LTT-9779 b is an inhabitant of the hot Neptune desert and one of only a few planets with a measured high albedo. Characterising the atmosphere of this world is the key to understan…

astro-ph.EP2026

Mass estimates of the young TOI-451 transiting planets: Multidimensional Gaussian Process on stellar spectroscopic and photometric signals

Oscar Barragán, Manuel Mallorquín, Jorge Fernández-Fernández +30

The young TOI-451 planetary system, aged 125 Myr, provides a unique opportunity to test theories of planetary internal structures and atmospheric mass loss through examination of i…

astro-ph.EP2024

Investigating stellar activity through eight years of Sun-as-a-star observations

Baptiste Klein, Suzanne Aigrain, Michael Cretignier +11

Stellar magnetic activity induces both distortions and Doppler-shifts in the absorption line profiles of Sun-like stars. Those effects produce apparent radial velocity (RV) signals…

astro-ph.EP2025

Using Doppler Imaging to model stellar activity and search for planets around Sun-like stars

Baptiste Klein, Suzanne Aigrain, Michael Cretignier +9

Doppler Imaging (DI) is a well-established technique to map a physical field at a stellar surface from a time series of high-resolution spectra. In this proof-of-concept study, we…

astro-ph.EP2024

TOI-837b is a Young Saturn-sized Exoplanet with a Massive 70 Core

Oscar Barragán, Haochuan Yu, Alix Violet Freckelton +10

We present an exhaustive photometric and spectroscopic analysis of TOI-837, a F9/G0 35 Myr young star, hosting a transiting exoplanet, TOI-837b, with an orbital period of 8.32d. Ut…

astro-ph.EP2024

Modelling stellar variability in archival HARPS data: I -- Rotation and activity properties with multi-dimensional Gaussian Processes

Haochuan Yu, Suzanne Aigrain, Baptiste Klein +4

Although instruments for measuring the radial velocities (RVs) of stars now routinely reach sub-meter per second accuracy, the detection of low-mass planets is still very challengi…

astro-ph.EP2026

Spin-Orbit Geometry of AU Mic b and c from Back-to-Back Transits Observed Contemporaneously with Magellan PFS, LCOGT, and CHEOPS

Zitao Lin, Gyula M. Szabó, Krzysztof Sz. Zieliński +37

Young planets offer a unique window into the early stages of planetary evolution. AU Mic is one of the nearest (9.8 pc) pre-main sequence stars (~20 Myr), hosting two transiting Ne…

astro-ph.EP2021

Mapping the 3D Kinematical Structure of the Gas Disk of HD 169142

Haochuan Yu, Richard Teague, Jaehan Bae +1

The disk around HD 169142 has been suggested to host multiple embedded planets due to the range of structures observed in the dust distributions. We analyze archival ALMA observati…

astro-ph.EP2023

Revisiting K2-233 spectroscopic time-series with multidimensional Gaussian Processes

Oscar Barragán, Edward Gillen, Suzanne Aigrain +7

Detecting planetary signatures in radial velocity time-series of young stars is challenging due to their inherently strong stellar activity. However, it is possible to learn inform…