256 citations · 2.1k across the 57 of their papers we have counts for
57 papers
WOCS XCIII: NGC 7789: the Evolution of Li, Stellar Rotation, and Extended Main Sequence Turnoffs
Barbara J. Anthony-Twarog, Samantha W. Brunker, Constantine P. Deliyannis +4
Precision UBVRI photometry of NGC 7789 is combined with Gaia data to map reddening variations across the cluster face. HYDRA spectra, Gaia astrometry, and isochrone fitting constra…
Lithium Abundances of Main-Sequence Stars in the Old Open Cluster NGC 188: Probes of Stellar Evolution Beyond the Solar Age
Qinghui Sun, Constantine P. Deliyannis, Bruce A. Twarog +1
We present lithium abundances for 119 main-sequence stars in the old open cluster NGC 188 (age = 6.3 Gyr), using high-resolution, high signal-to-noise ratio spectra from WIYN/Hydra…
Subgiants in NGC 188 Reveal that Rotationally Induced Mixing Creates the Main Sequence Li-Dip
Qinghui Sun, Constantine P. Deliyannis, Barbara J. Anthony-Twarog +3
The "Li-Dip" is an unexpected, striking, and highly non-standard anomaly of severe lithium depletion observed in mid-F dwarf stars, which has puzzled astronomers for nearly 40 year…
Li Evolution Among Stars of Low/Intermediate Mass: The Metal-Deficient Open Cluster, NGC 2204
Barbara J. Anthony-Twarog, Constantine P. Deliyannis, Aaron Steinhauer +2
We have analyzed high-dispersion spectra in the Li 6708 Angstrom region for 167 stars within the anticenter cluster, NGC 2204. From 105 probable members, abundance analysis of 45 e…
Primordial Lithium from Globular Cluster Turn-Off Stars: M13 AND M71
Ann Merchant Boesgaard, Constantine P. Deliyannis
During Big Bang nucleosynthesis (BBN) in the first 15 minutes of the Universe some Li was created along with isotopes of H and He. The determination of that primordial value of…
Lithium in Turn-off Stars in the Globular Cluster M5: A Quest for Primordial Lithium
Ann Merchant Boesgaard, Constantine P. Deliyannis
The light element lithium is formed by nucleosynthesis during the Big Bang. Its abundance can help to define the parameters of the early universe. To find this primordial value, it…