GCN Circular 15060
W. Fong and E. Berger (Harvard) report: "We inspected the second epoch of HST WFC3/F160W imaging of the short GRB 130603B obtained on 2013 July 3.24 UT. Digital image subtraction relative the first epoch (on 2013 June 13.15 UT) reveals that the near-IR point source coincident with the afterglow position has faded away, confirming our original suggestion that it is associated with GRB 130603B (Berger et al. 2013 arXiv:1306.3960). The subtraction also confirms our brightness measurement, with m(F160W)=25.8 AB mag. Coupled with an early steep decline in the optical band based on additional Magellan/IMACS observations at 32.2 hr post-burst, with r>24.8 AB mag (see also Cucchiara et al. 2013, arXiv:1306.2028; Tanvir et al. 2013, arXiv:1306.4971) this confirms the likely kilonova origin of this source."