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Chemical Abundances of M-dwarfs from the APOGEE Survey. I. The Exoplanet Hosting Stars Kepler-138 and Kepler-186
Diogo Souto, Katia Cunha, D. A. Garcia-Hernandez +18
We report the first detailed chemical abundance analysis of the exoplanet-hosting M-dwarf stars Kepler-138 and Kepler-186 from the analysis of high-resolution ( 22,500) $…
Chemical Abundances in a Sample of Red Giants in the Open Cluster NGC 2420 from APOGEE
Diogo Souto, Katia Cunha, Verne Smith +20
NGC 2420 is a 2 Gyr-old well-populated open cluster that lies about 2 kpc beyond the solar circle, in the general direction of the Galactic anti-center. Most previous abundan…
ASPCAP: The Apogee Stellar Parameter and Chemical Abundances Pipeline
Ana E. García Pérez, Carlos Allende Prieto, Jon A. Holtzman +27
The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has built the largest moderately high-resolution (R=22, 500) spectroscopic map of the stars across the Milky Way…
Evidence for a metal-poor population in the inner Galactic Bulge
M. Schultheis, K. Cunha, G. Zasowski +14
The inner Galactic Bulge has, until recently, been avoided in chemical evolution studies due to extreme extinction and stellar crowding. Large, near-IR spectroscopic surveys, such…
Exploring Anticorrelations and Light Element Variations in Northern Globular Clusters Observed by the APOGEE Survey
Szabolcs Meszaros, Sarah L. Martell, Matthew Shetrone +20
We investigate the light-element behavior of red giant stars in Northern globular clusters (GCs) observed by the SDSS-III Apache Point Observatory Galactic Evolution Experiment (AP…
Sodium and Oxygen Abundances in the Open Cluster NGC 6791 from APOGEE H-Band Spectroscopy
Katia Cunha, Verne V. Smith, Jennifer A. Johnson +27
The open cluster NGC 6791 is among the oldest, most massive and metal-rich open clusters in the Galaxy. High-resolution -band spectra from the Apache Point Observatory Galactic…
The APOKASC Catalog: An Asteroseismic and Spectroscopic Joint Survey of Targets in the Kepler Fields
Marc H. Pinsonneault, Yvonne Elsworth, Courtney Epstein +42
We present the first APOKASC catalog of spectroscopic and asteroseismic properties of 1916 red giants observed in the Kepler fields. The spectroscopic parameters provided from the…
Bayesian distances and extinctions for giants observed by Kepler and APOGEE
Thaíse S. Rodrigues, Léo Girardi, Andrea Miglio +30
We present a first determination of distances and extinctions for individual stars in the first release of the APOKASC catalogue, built from the joint efforts of the Apache Point O…
Exploring the Origin of Lithium, Carbon, Strontium and Barium with four new Ultra Metal-Poor Stars
T. Hansen, C. J. Hansen, N. Christlieb +8
We present an elemental abundance analysis for four newly discovered ultra metal-poor stars from the Hamburg/ESO survey, with . Based on high-resolution, hig…
Testing the Asteroseismic Mass Scale Using Metal-Poor Stars Characterized with APOGEE and Kepler
Courtney R. Epstein, Yvonne P. Elsworth, Jennifer A. Johnson +29
Fundamental stellar properties, such as mass, radius, and age, can be inferred using asteroseismology. Cool stars with convective envelopes have turbulent motions that can stochast…
Spectroscopic signatures of youth in low-mass kinematic candidates of young moving groups
M. C. Gálvez-Ortiz, M. Kuznetsov, J. R. A. Clarke +12
We present a study of age-related spectral signatures observed in 25 young low-mass objects that we have previously determined as possible kinematic members of five young moving gr…
Calibrations of Atmospheric Parameters Obtained from the First Year of SDSS-III APOGEE Observations
Sz. Mészáros, J. Holtzman, A. E. García Pérez +25
The SDSS-III Apache Point Observatory Galactic Evolution Experiment (APOGEE) is a three year survey that is collecting 100,000 high-resolution spectra in the near-IR across multipl…
Very Metal-poor Stars in the Outer Galactic Bulge Found by the Apogee Survey
Ana E. García Pérez, Katia Cunha, Matthew Shetrone +27
Despite its importance for understanding the nature of early stellar generations and for constraining Galactic bulge formation models, at present little is known about the metal-po…
Chemical Abundances in Field Red Giants from High-Resolution H-Band Spectra using the APOGEE Spectral Linelist
Verne V. Smith, Katia Cunha, Matthew D. Shetrone +8
High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory (KPNO) Fourier Transform Spectrometer (FTS…
The barium isotopic fractions in five metal-poor stars
A. J. Gallagher, S. G. Ryan, A. Hosford +3
We provide measurements of the Ba isotopic fractions for five metal-poor stars derived with an LTE analysis using 1D model stellar atmospheres. We use high resolution (R\equivλ/Δλ=…
The barium isotopic mixture for the metal-poor subgiant star HD140283
A. J. Gallagher, S. G. Ryan, A. E. García Pérez +1
Current theory regarding heavy element nucleosynthesis in metal-poor environments states that the r-process would be dominant. The star HD140283 has been the subject of debate afte…
Spectroscopy and kinematics of low-mass members of young moving groups
M. C. Galvez-Ortiz, J. R. A. Clarke, D. J. Pinfield +8
We study a target sample of 68 low-mass objects (with spectral types in the range M4.5-L1) previously selected via photometric and astrometric criteria, as possible members of five…
Lithium abundances of halo dwarfs based on excitation temperatures. II. NLTE
A. Hosford, A. E. Garcia Perez, R. Collet +3
One of the most important factors in determining the stellar lithium abundance is the effective temperature. In a previous study by the authors, new effective temperatures Teff for…
Lithium Abundances of Extremely Metal-Poor Turn-off Stars
Wako Aoki, Paul S. Barklem, Timothy C. Beers +5
We have determined Li abundances for eleven metal-poor turn-off stars, among which eight have [Fe/H]<-3, based on LTE analyses of high-resolution spectra obtained with the HDS on t…