TITLE: GCN CIRCULAR NUMBER: 14770 SUBJECT: GRB 130603B: MASTER-Net early observations and optical sloap limit DATE: 13/06/05 17:11:24 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs Maria Pruzhinskaya, D.Denisenko, E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov Sternberg Astronomical Institute, Lomonosov Moscow State University K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University, Irkutsk V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov, A.Gabovich Blagoveschensk Educational State University, Blagoveschensk A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinski, I.Zalozhnih, A. Popov Ural Federal University, Kourovka Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA) MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Tunka was pointed to GRB130603B 35 sec after Notice time and 52 sec after Trigger time (Melandri et al., GCN 14735) in two mutually perpendicular polarizations. We didn't find OT at the position reported by Levan et al., GCN 14742 and A. de Ugarte Postigo et al., GCN 14743. Our photometry (upper limits) during the first 20 minutes until the clouds started coming in is as follows: t_UT Exp T-T_trig Limit Filter Tube ------------------------------------------------------- 2013-06-03 15:50:06 10 52 15.4 P| EAST 2013-06-03 15:50:07 10 53 15.1 P- WEST 2013-06-03 15:51:06 20 112 15.9 P| EAST 2013-06-03 15:51:07 20 113 15.8 P- WEST 2013-06-03 15:52:08 30 174 16.2 P| EAST 2013-06-03 15:52:08 30 174 16.1 P- WEST 2013-06-03 15:53:18 50 244 16.7 P| EAST 2013-06-03 15:53:19 50 245 16.7 P- WEST 2013-06-03 15:55:01 70 348 16.7 P| EAST 2013-06-03 15:55:02 70 349 16.6 P- WEST 2013-06-03 15:56:48 90 454 17.2 P| EAST 2013-06-03 15:56:49 90 455 16.9 P- WEST 2013-06-03 15:58:57 120 583 17.6 P| EAST 2013-06-03 15:58:58 120 584 17.5 P- WEST 2013-06-03 16:01:43 150 749 18.0 P| EAST 2013-06-03 16:01:43 150 749 17.6 P- WEST 2013-06-03 16:04:54 180 940 18.0 P| EAST 2013-06-03 16:04:54 180 940 17.5 P- WEST The OT upper limit available on the plot : http://master.sai.msu.ru/static/OT/grb130306B.gif We have tried to compare our data with the photometry from the large telescopes in the filters similar to ours. In fact, we have used the observations in r filter. The following data have been published so far. Afterglow: t+5.8 hours r=20.94 WHT Levan et al., GCN 14742 t+5.8 hours r=20.9 NOT A. de Ugarte Postigo et al., GCN 14743 t+7.5 hours r=21.2 Gemini-South Cucchiara et al., GCN 14748 Large aperture to include both objects: t+12.2 hours r'=20.8 P60 (Palomar 60 inch) Cenko et al., GCN 14761 t+14.78 hours r'=20.78 RATIR (1.5m Harold Johnson) Eleonora Troja et al., GCN 14764 We were not able to use the Swift UVOT data in the white light (De Pasquale et al., GCN 14759) since their exact times of mid-exposures are not easy to determine. Obviously, the last two points involve the host galaxy. In order to constrain the slope we have used the data from WHT, NOT and Gemini South. The results are presented here: http://master.sai.msu.ru/static/OT/grb130306B_all.gif Thus, supposing the power law of the fading afterglow F ~ t^-alpha we are providing the following limitation: alpha < 0.84. The message may be cited.