Faint star studies in the Magellanic clouds. II. Field regions 9 northeast of the Large Magellanic Cloud.
Abstract
Photographic photometry is reported for 16 far-halo-field regions. These fields lie 9.1 deg northeast of the LMC bar, surrounding the old globular cluster NGC 2257. Field color-magnitude diagrams show a red horizontal branch, a subgiant branch redder than that of the cluster, and a profusion of blue stars delineating a younger main sequence. Possible sources of the blue stars are discussed. The field is significantly younger than the cluster, showing that star formation, even in the outer regions of the LMC where the gas density is presently minimal, proceeded long after the formation of the old clusters. It appears that the major portion of stars in the LMC is of intermediate age. That this is true of a region 9 kpc from the bar is of great importance to the eventual derivation of a global history of star formation in the LMC.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- June 1984
- DOI:
- 10.1086/190950
- Bibcode:
- 1984ApJS...55..127S
- Keywords:
-
- Astronomical Photography;
- Magellanic Clouds;
- Stellar Spectrophotometry;
- Blue Stars;
- Halos;
- Horizontal Branch Stars;
- Photographic Plates;
- Stellar Color;
- Stellar Evolution;
- Stellar Magnitude;
- Astronomy