{\sl HST} WFPC2 Observations of the M31 Nucleus and the M31 Globular Cluster G1

Previous abstract Next abstract

Session 76 -- Spirals I
Display presentation, Wednesday, 11, 1995, 9:20am - 6:30pm

[76.08] {\sl HST} WFPC2 Observations of the M31 Nucleus and the M31 Globular Cluster G1

R. Michael Rich (Columbia University), Kenneth J. Mighell (Columbia University), Wendy L. Freedman (Carnegie Observatories)

We present new Cycle 4 images of the brightest globular cluster, M31 G1=Mayall II. The I, V-I color-magnitude digram has a giant branch that falls on the locus of 47 Tuc, and a very red horizontal branch that is at our detection limit, at V=25.2; adopting a modulus of 24.4 mag, $M_V(HB)=+0.8$. While at the limit of detection, the horizontal branch is as red as the giant branch.

We also present Cycle 4 images of the M31 nucleus in the F1042M filter. The double morphology is identical to that reported by Lauer et al. [(1993) AJ 106, 1436]. Restored WFPC1 images [Rich, Mighell \& Neill, 1994 in preparation] show no change in morphology from 4400\AA\ to 8500\AA. These observations serve to further confirm that the peculiar morphology is not due to absorption by dust.

Wednesday program listing