IR photometry of the stars in Terzan 2

• Published in: The Astronomical journal 1992, Vol.103 (1), p.142-150
• Main Authors: CHRISTIAN, C. A, FRIEL, E. D
• Format: Article
• Language: English
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology; Globular clusters in the milky way; Stellar clusters and associations; Stellar systems. Galactic and extragalactic objects and systems. The universe
• ISSN: 0004-6256; 1538-3881
• DOI: 10.1086/116048

The giant branch of the globular cluster Terzan 2 has been studied using the Infrared Imaging Camera at the United Kingdom Infrared Telescope. An IR color-magnitude diagram of this object has been obtained to study this cluster relative to clusters with known metallicities and ages to determine independent estimates for the parameters relevant to Terzan 2. The Terzan clusters are important as they are among the most metal-rich members of the so-called disk component of the globular cluster system, but they are located in a direction very close to the galactic center; hence, observations are particularly difficult due to interstellar obscuration. Assuming that the cluster has Fe/H about -0.25 (Armandroff and Zinn, 1988), Terzan 2 is found to be at an intrinsic distance modulus of 15.0 +/-0.2 mag with a reddening E(B-V) = 1.25 +/-0.15. At the corresponding distance, 10 kpc, the cluster is located approximately 440 pc above the disk, well within the bulge of the galaxy. (Author)