Supergiants and the Galactic metallicity gradient. II - Spectroscopic abundances for 64 distant F- to M-type supergiants

Abstract

view Abstract Citations (57) References (42) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Supergiants and the Galactic Metallicity Gradient. II. Spectroscopic Abundances for 64 Distant F- to M-Type Supergiants Luck, R. Earle ; Bond, Howard E. Abstract The metallicity gradient in the Galactic disk from in situ stars with visual magnitude ranging from 6 to 10 is analyzed. Atmospheric parameters and detailed chemical abundances for 64 Population I supergiants of spectral types F through M and luminosity classes Ia through II have been determined. The derived Fe/H ratios ranging from -0.5 to + 0.7 show a mean value of +0.13 with an estimated uncertainty of + or - 0.2. A subset of 25 supergiants fainter than 7th magnitude lying in the direction of the Galactic center shows a Fe/H mean of +0.18 + or - 0.04, while a similar sample of 15 faint supergiants lying in the direction of the Galactic anticenter shows a lower Fe/H mean of +0.07 + or - 0.06. For a sample of bright supergiants analyzed by Luck and Lambert (1985), the mean abundance pattern for all 64 stars showed the following: deficient C and O along with enhancement of N, indicating mixing of CNO-cycled material to the stellar surfaces; an apparent Sr enhancement attributed to departures from LTE; and an essentially solar pattern of other chemical elements. Publication: The Astrophysical Journal Supplement Series Pub Date: November 1989 DOI: 10.1086/191386 Bibcode: 1989ApJS...71..559L Keywords: Abundance; F Stars; M Stars; Metallicity; Stellar Spectra; Supergiant Stars; Astronomical Photography; Spectral Line Width; Stellar Color; Stellar Luminosity; Astrophysics; STARS: ABUNDANCES; STARS: LATE-TYPE; STARS: SUPERGIANTS full text sources ADS | data products SIMBAD (158) Related Materials (1) Part 1: 1982ApJ...263..215L