Color Indices and Integrated Magnitudes of Fifteen Bright Globular Clusters
Abstract
Extra-focal photographs of fifteen globular clusters were obtained in blue and in yellow light with two short-focus cameras. It is found that the lower the galactic latitude of a cluster, the redder is its color. The increase in color corresponds to a differ- ential absorption of o~i i ± .02 encountered by light passing perpendicularly through the Milky Way. The derived integrated apparent magnitudes of the clusters lead to integrated absolute magnitudes which, on the average, are 2 mag. brighter than the integrated absolute magnitudes of Hubble's objects connected with M ~ i which he has provisionally identified as globular clusters
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1933
- DOI:
- 10.1086/143472
- Bibcode:
- 1933ApJ....77..301V