5 papers
TESS Asteroseismology of Red Giants in the Old Metal-Rich Open Clusters NGC 188 & NGC 6791
Madeline Howell, Jennifer A. Johnson, Marc H. Pinsonneault +5
Open clusters are fundamental laboratories for investigating stellar and Galactic evolution, and serve as important benchmarks for asteroseismic analyses. Using a boutique method t…
Challenges to the Two-Infall Scenario by Large Stellar Age Catalogs
Liam O. Dubay, Jennifer A. Johnson, James W. Johnson +1
Stars in the Milky Way disk exhibit a clear separation into two chemically distinct populations based on their [/Fe] ratios. This -bimodality is not a universal feature of…
Stellar Parameters of BOSS M dwarfs in SDSS-V DR19
Dan Qiu, Jennifer A. Johnson, Chao Liu +15
We utilized the Stellar LAbel Machine (SLAM), a data-driven model based on Support Vector Regression, to derive stellar parameters ([Fe/H], , and ) for SDSS-V…
The Initial mass function of field stars with mass 1 varies with metallicity
Dan Qiu, Chao Liu, Jennifer A. Johnson +2
We investigated a volume-limited sample of LAMOST main-sequence stars with masses from 0.25 to 1 and distances of 150-350 pc to explore how the stellar initial mass fun…
[C/N] Ages for Red Giants and their Implications for Galactic Archaeology
John D. Roberts, Marc H. Pinsonneault, Jennifer A. Johnson +2
Red giants undergo the first dredge-up, a mixing event that creates a connection between their surface [C/N] and their mass and age. We derive a [C/N]-Age relationship for red gian…