Color-magnitude diagram for the globular cluster M 22.
Abstract
. Photovisual and photographic magnitudes of more than 400 stars in the globular cluster M22 have been measured. The resulting color-magnitude diagram extends to slightly fainter than the RR Lyrae domain and is generally similar to those for other globular clusters, in particular most resembling the diagram for M13. Using the customary assumption that the mean magnitude of the RR Lyrae stars is Mp0 = 0.0, an apparent distance modulus of 14.0 mag. and a reddening of 0.5 mag. are derived. The distance of the cluster is, therefore, 3.3 kpc and its brightest stars have M = -3.0 and CL = +1.6 mag.
- Publication:
-
The Astronomical Journal
- Pub Date:
- February 1959
- DOI:
- 10.1086/107848
- Bibcode:
- 1959AJ.....64...28A