TITLE: GCN CIRCULAR NUMBER: 7710 SUBJECT: GRB 080319B: Further HST observations and underlying host DATE: 08/05/12 18:35:30 GMT FROM: Andrew Levan at U.of Leicester A.J. Levan (U. Warwick), N.R. Tanvir (U. Leicester), A.S. Fruchter (STScI) and J. Graham (STScI) report: We have obtained a second epoch of HST observations of GRB 080319B on 11 May 2008. 2 orbits (3200s) of observations were taken in the F606W and F814W filters. The afterglow has clearly faded from our first epoch of observations and a faint host galaxy is now visible at the afterglow location. We measure magnitudes for the combined (afterglow+host) source of; F606W(AB)=26.3 +/ -0.1 F814W(AB)=25.9 +/ -0.1 Relative astrometry between the two epochs of HST observations suggests that the afterglow is marginally (0.1 +/- 0.05 arcseconds) offset from the centroid of the host galaxy in the F606W image. This implies that the afterglow may not be the dominant source of light at the current epoch, and is likely significantly fainter than the magnitudes quoted above.