Published October 1979 | Version v1
Journal article

UBV photometry of RR Lyrae variables in the globular cluster NGC 6121 (M4)

Creators

  • 1. Mount Stromlo and Siding Spring Observatories, Research School of Physical Sciences, The Australian National University

Description

Photometry in U, B, and V is reported for 11 RR Lyrae variables and 11 horizontal branch stars in the globular cluster NGC 6121 (M4). The variables cover the whole range of periods present. From the present data and Sturch's (1977) observations of 15 ab-type RR Lyraes the reddening E/sub B/-V=0.36 +- 0.02 mag and the metal abundance [Fe/H]=-1.0 +- 0.4 are derived. Detailed comparisons are made with the results of pulsation theory and the following physical quantities for the variables in M4 are derived: Y=0.28 +- 0.05 and M=0.6 +- 0.1 M/sub sun/ assuming that Mv=0.6 +- 0.1 mag

Additional details

Publishing Information

Journal Title
Astron. J.
Journal Volume
84
Journal Issue
10
Series
Astron. J.
Journal Page Range
1542-1552
ISSN
0004-6256

INIS

Country of Publication
United States
Country of Input or Organization
United States
INIS RN
11515528
Subject category
S79: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY;
Descriptors DEI
CHEMICAL COMPOSITION; INTERSTELLAR GRAINS; INTERSTELLAR SPACE; IRON IONS; PHOTOMETRY; RED GIANT STARS; STAR CLUSTERS; VARIABLE STARS
Descriptors DEC
ATOMIC IONS; CHARGED PARTICLES; GIANT STARS; IONS; PARTICLES; SPACE; STARS