Evidence for an abundance gradient in the galactic disk.
Abstract
DDO photometry of field K giants in distant parts of the galactic disk in the galactic center and anticenter directions is used together with DDO and UBV photometry of 41 open clusters to investigate the variation of metallicity across the galactic disk. Some problems in the calibration of DDO photometry are examined, and the observations are analyzed. The data are shown to be consistent with the suggestion that there is a composition gradient among stars of all ages in the galactic disk. Specifically, it is found that: (1) the metallicity gradient in the solar vicinity is approximately -0.05/kpc; (2) the gradient may become steeper beyond a galactocentric distance of approximately 11 kpc; (3) the nitrogen gradient is more pronounced than the overall gradient; and (4) the gradient in the youngest stellar population is probably not dramatically different from the overall gradient
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- February 1979
- DOI:
- 10.1086/190568
- Bibcode:
- 1979ApJS...39..135J
- Keywords:
-
- Abundance;
- Giant Stars;
- Heavy Elements;
- Milky Way Galaxy;
- Stellar Spectrophotometry;
- Ubv Spectra;
- Astronomical Maps;
- Chronology;
- Interstellar Extinction;
- K Stars;
- Open Clusters;
- Stellar Evolution;
- Tables (Data);
- Astronomy;
- DDO Photometry:Galactic Disk;
- Galactic Disk:UBV Photometry