22 papers
Host--Non-host Differences in Stellar Chemistry, Activity, and Birth Radius: Hints of Distinct Formation Environments for Earth-like Planets and Sub-Neptunes
Xunzhou Chen, Tiancheng Sun, Yuxi +3
Host-star properties provide important clues to planet formation and evolution, yet it remains unclear whether the observed differences between planet-hosting stars and stars witho…
They Won't Be Giants: Missing Metal-Rich RGB Stars in Gaia Data Indicate Truncated Stellar Evolution
Yuxi Lu, Madeline Howell, Marc H. Pinsonneault +3
We investigate the population of luminous red giant branch stars as a function of metallicity using Gaia XP metallicity combined with SDSS-V, GALAH, and LAMOST. After applying unif…
The Twentieth Data Release of the Sloan Digital Sky Survey: First All-Sky BOSS Spectra, eROSITA-SDSS-V Mapper Coordinated Observations, and a Preview of the Local Volume Mapper
SDSS Collaboration, Mojgan Aghakhanloo, David Aguilar +273
The paper describes the twentieth data release (DR20) of the Sloan Digital Sky Survey, providing over 3 million new optical spectra from the SDSS‑V Milky Way, Black Hole, and Local…
Ensemble Kinematic Ages for 1.5 Million LAMOST Stars
Yuxi Lu, Marc H. Pinsonneault
We present a framework for inferring stellar ages from spectroscopic stellar parameters, calibrated with ensemble kinematics by averaging over the median vertical action, , fo…
Insights into the Exoplanet Radius Valley from Host-Star Ages, Activity, Chemistry, and Birth Radius
Xunzhou Chen, Tiancheng Sun, Yuxi +3
The radius valley, a bimodal feature in the size distribution of close-in small exoplanets, is widely interpreted as a signature of atmospheric loss and therefore provides a key co…
[C/N] Ages and Extra-Mixing for [Fe/H] <- 0.5: Insights from the LMC and SMC
Yuxi Lu, John D. Roberts, Joshua T. Povick +4
The [C/N]-age relation has become a powerful tool for reconstructing the formation history of the Milky Way (MW), providing the largest age sample for field giant stars. However, a…