J/AJ/114/1488 J/AJ/114/1488 Globulars in M31 S Holland G G Fahlman H B Richer Astron. J. 114 1488 1997 1997AJ....114.1488H Clusters, globular Photometry We present deep (V=~27) V- and I-band stellar photometry of G302 and G312, two globular star clusters in the halo of M31. These data were obtained using the Hubble Space Telescope's Wide Field/Planetary Camera 2. We find iron abundances of [Fe/H]=-1.85+/-0.12 for G302 and [Fe/H]=-0.56+/-0.03 for G312, consistent with spectroscopic measurements. The color-magnitude diagrams for each cluster show no evidence for an intermediate-aged population of stars, or a second parameter effect in the morphology of the horizontal branch. G302 shows no evidence for a color gradient but the inner regions of G312 are bluer than the outer regions. G312 shows no evidence of ellipticity or an extended halo of stars. G302 has a projected ellipticity of {epsilon}=0.195+/-0.012 with the projected major axis oriented towards the center of M31. G302 also shows evidence of an extended asymmetric stellar halo extending to at least twice the fitted Michie-King tidal radius. The amount of mass beyond the tidal radius of G302 is consistent with the stellar escape rates which have been predicted by N-body simulations of globular clusters in the Galactic tidal field. (c) 1997 American Astronomical Society.

HST G302SKHB 302Bol 24000 45 25.2+41 05 30 G312SKHB 312Bol 37900 45 58.8+40 42 32

CCD CCD the star was observed on --- ID Identification number number=1 Identification numbers are only unique for stars on a given CCD. --- Xpos X pixel coordinate number=2 1 pix = 0.1". pix Ypos Y pixel coordinate number=2 1 pix = 0.1". pix Vmag V-band magnitude mag e_Vmag 1-sigma uncertainty in Vmag mag 2_Vmag Value of the DAOPHOT Chi statistics for Vmag --- Imag I-band magnitude mag e_Imag 1-sigma uncertainty in Imag mag 2_Imag Value of the DAOPHOT Chi statistics for Imag --- CCD CCD the star was observed on --- ID Identification number --- Xpos X pixel coordinate number=1 1 pix = 0.1". pix Ypos Y pixel coordinate number=1 1 pix = 0.1". pix Dist Distance of star from cluster center arcsec Vmag V-band magnitude mag e_Vmag 1-sigma uncertainty in Vmag mag 2_Vmag Value of the DAOPHOT Chi statistics for Vmag --- Imag I-band magnitude mag e_Imag 1-sigma uncertainty in Imag mag 2_Imag Value of the DAOPHOT Chi statistics for Imag --- tables.texAASTeX version of the tables tables.psPostScript version of the tables CDS 1998Feb05AAS CD-ROM series, Volume 9, 1997 Lee Brotzman [ADS] 04-Nov-1997 J_AJ_114_1488.xml