TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1134 SUBJECT: GRB 970828: HST Observations of the Host Galaxy DATE: 01/11/07 06:48:01 GMT FROM: Josh Bloom at CIT GRB 970828: HST Observations of the Host Galaxy J. S. Bloom, S. R. Kulkarni, T. J. Galama, D. A. Frail and S. G. Djorgovski report on behalf the larger Caltech-NRAO-CARA GRB Collaboration: "We observed the field of GRB 970828 (Remillard et al., IAUC 6726; Murakami et al., IAUC 6732; Groot et al. 1998, ApJ, 493, 27) on 2001 August 16-18 UT using the WFPC F450W, F606W, F814W filters on the Hubble Space Telescope. The total integration time in each filter was 8800 s. The 3-component host system seen in deep Keck imaging (Djorgovski et al. 2001, astro-ph/0107539, accepted) appears to be spatially resolved, with no detected emission connecting the components. However, given the signal-to-noise, we would be unable to detect low-surface brightness features and cannot therefore make a strong claim about the geometry of dust and stars in the system. Astrometrically comparing the F606W images with the Keck localization, we identify component "B" (from figure 3 of Djorgovski et al.) as the host galaxy. The offset location and uncertainty (which is large due to the poor astrometric tie between radio and optical images) are consistent with those reported in Bloom, Kulkarni & Djorgovski (2001; astro-ph/0010176). An image of the host may be found at: http://www.astro.caltech.edu/~jsb/GRB/grb970828-host-reg.ps The 3-sigma uncertainty contour of the OT position is shown in this image as well as the galaxy component labels from Djorgovski et al." This message may be cited.