C-J0907-372 (PYXIS) - A NEW DISTANT GALACTIC GLOBULAR-CLUSTER

The prime-focus camera of the Angle-Australian Telescope has been used to image the object listed by Weinberger (PASP, 107, 58, 1995) as a p ossible distant star cluster or dwarf spheroidal galaxy. The CCD data reveal this object to be a distant globular cluster of low central con centration. In particular, the color-magnitude diagram for the cluster core shows a sparse giant branch, a prominent red horizontal branch a t R=18.75 and a main-sequence turnoff near the Limit of the data at R approximate to 22.0. A population of possible blue stragglers is also evident. Based on comparisons with the giant branches of standard glob ular clusters, the reddening to this cluster, designated C J0907 - 372 (Pyxis), is estimated to be 0.25 less than or equal to E(B - V) less than or equal to 0.40. The cluster is then approximately 35 kpc from t he Sun and 37 kpc from the galactic center. With a core radius of simi lar to 14 pc, an estimated absolute magnitude M(V) approximate to-5.7 and a dominant red horizontal branch, C J0907 - 372 (Pyxis) has very s imilar properties to the other low-luminosity globular clusters of the outer galactic halo.