GRB 100728b t-t0 = 10:31:55 = 37915 S RA = 02:56:13.46 Dec = +00:16:51.9 refstars N id u g r i z RA h m s Dec d ' '' R 1 J025634.13+001736.3 19.798 17.665 16.839 16.518 16.358 02:56:34.140 +00:17:36.37 16.596 2 J025634.77+001631.0 18.639 17.259 16.73 16.54 16.433 02:56:34.772 +00:16:31.03 16.533 3 J025607.18+001336.0 20.845 18.337 16.897 15.838 15.294 02:56:7.185 +00:13:36.05 16.489