activity
20242026
collaborators

15 papers

astro-ph.SR2026

The Fe I 4377 Ã Line as a Solar Faculae Indicator: Insights from Spectral Ratio Analysis

Katlyn L. Hobbs, Christopher A. Watson, Jean C. Costes +21

Faculae are a dominant source of stellar activity noise in radial velocity measurements, yet their low contrast and broad surface distribution make them difficult to track in disc-…

astro-ph.EP2026

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.IM2026

Scalable Gaussian Processes for Integrated and Overlapping Measurements Via Augmented State Space Models

Ryan A. Rubenzahl, Soichiro Hattori, Simo Särkkä +4

Astronomical measurements are often integrated over finite exposures, which can obscure latent variability on comparable timescales. Correctly accounting for exposure integration w…

astro-ph.IM2026

Exposure-averaged Gaussian Processes for Combining Overlapping Datasets

Jacob K. Luhn, Ryan A. Rubenzahl, Samuel Halverson +1

Physically motivated Gaussian process (GP) kernels for stellar variability, like the commonly used damped, driven simple harmonic oscillators that model stellar granulation and p-m…

astro-ph.EP2026

The KPF-SLOPE Survey - Small, Compact Multi-Planet Systems Appear Spin-Orbit Aligned

Luke B. Handley, Andrew W. Howard, Fei Dai +16

The angle between stellar spin axes and planetary orbits -- stellar obliquity -- probes the dynamics of planetary migration and evolution. The obliquities of giant planets have bee…

astro-ph.EP2026

Evidence for a Peak at 0.3 in the Eccentricity Distribution of Typical Super-Jovian Exoplanets

Sarah Blunt, Jason Wang, Ruth Murray-Clay +3

In this study, we compute completeness-corrected occurrence rates of giant exoplanets as a function of mass, semimajor axis, and eccentricity, using the approximately uniform Calif…