ADS Astronomy Abstract Service

Title:		Infrared Photometry of the Globular Cluster Terzan 6
Authors:		FAHLMAN, G. G.; DOUGLAS, K. A.; THOMPSON, I. B.
Journal:		Astronomical Journal v.110, p.2189
Publication Date:		11/1995
Origin:		AJ
AJ Keywords:		GLOBULAR CLUSTERS: INDIVIDUAL: TERZAN 6
Bibliographic Code:		1995AJ....110.2189F

Abstract

The highly reddened globular cluster Terzan 6 lies in the direction of the galactic center. Published distance estimates, based on very uncertain values for the visual magnitude of the cluster horizontal branch and the interstellar reddening place the cluster either on the far side of the galactic center at distance of 12.8 kpc or at distance of only 1.5 kpc. If at the near distance, Ter 6 is the closest globular cluster to the Sun. The cluster exhibits a collapsed core and contains a ROSAT x-ray source. We present new infrared photometry obtained with the Las Campanas NICMOS3 Camera. The (K, J-K) colour-magnitude diagram clearly reveals the location of the horizontal branch. Through a comparison with IR photometry of stars in the similar metallicity cluster M71, we calculate that the reddening to Ter 6 is E(B-V)=2.04 mag and determine the cluster distance to be 6.80+/-0.46 kpc.