{
  "bibcode": "2005GCN..3646....1Z",
  "body": "A. Zeh, D. A. Kann, S. Klose (Thueringer Landessternwarte Tautenburg, Germany),\nA. Manning, C. Riddle (Clemson University, SC, USA),\n\nreport:\n\nWe observed the field of GRB 050712 (Grupe et al. 2005, GCN 3573) with\nthe Tautenburg 1.34m Schmidt telescope in the R filter at two epochs.\n\nThe first set of observations consisted of 10 x 30 second exposures,\nmid-exposure time UT 050712.937, i.e. 0.353 days after the GRB. The\nsecond set of observations consisted of 20 x 30 second exposures,\nmid-exposure time UT 050713.948, i.e. 1.364 days after the burst.\n\nA comparison of our combined first epoch image with our deeper second\nepoch image shows that the potential optical counterpart of the afterglow\n(Zeh et al. 2005, GCN 3587) has faded away. Thus, we confirm the earlier\nreport by Rol et al. (2005, GCN 3575) that the source at coordinates RA,\nDEC (J2000) = 5:10:48.1, +64:54:47.6 is the optical counterpart of the\nX-ray afterglow (Falcone et al. 2005, GCN 3574; Grupe et al. 2005, GCN 3579).\n\nAssuming R = 15.8 for the USNO-A2.0 star U1500_0409875 at RA, DEC (J2000)\n= 05:11:10.51, +64:55:36.0 (Maiorano et al. 2005, GCN 3601), we find the\nfollowing magnitudes for the GRB 050712 afterglow:\n\nUT mid\t\tt-t_0 (days)\t mag_Rc\n\n12.937\t\t0.353\t          20.7 +/- 0.4\n13.948\t\t1.364    \t> 21.5\n\nWe find that the decay slope alpha is  about 1.2 using the data point by Maiorano \net al. (2005, GCN 3601).  \n\nThis message may be cited.",
  "circularId": 3646,
  "createdOn": 1121790134000,
  "email": "zeh@tls-tautenburg.de",
  "subject": "GRB 050712, Tautenburg optical afterglow observations",
  "submitter": "Andreas Zeh at TLS Tautenburg  <zeh@tls-tautenburg.de>",
  "eventId": "GRB 050712"
}