TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3609 SUBJECT: GRB 050714, optical observations DATE: 05/07/14 10:49:34 GMT FROM: Sylvio Klose at TLS Tautenburg S. Klose, B. Stecklum, B. Fuhrmann, F. Ludwig, Thueringer Landessternwarte Tautenburg, and J. Greiner, MPE Garching, report: The field of GRB 050714 was observed with the Tautenburg Schmidt telescope using for the first time the semi-robotic mode. In this mode the telescope software is watching for a special SMS message created in Garching which is extracted from the BACODINE notifications. As a result, if a burst happens the coordinates of the GRB error box are automatically uploaded into the current target data file, and the telescope software is waiting for an OK to be given by the telescope operator. In this respect human intervention is mandatory, so that this mode is not fully robotic (which is indeed not forseen because of security reasons). Observations of GRB 050714 started at 0:24 UT on July 14, i.e. 18 min after the onset of the burst (Gotz et al. 2005, GCN 3607). A sequence of several I, R, and V-band images was taken starting with the I-band (several 2 min exposures). Observations continued until 1:50 UT (twilight). A first inspection of the combined images shows no new bright source in the GRB error circle (90% c.l.; Gotz et al. 2005). However, we detect two potentially variable objects. Source #1, at RA, DEC (J2000) 02:54:47.05, 69:08:04.2, is listed in the USNO-B catalogue. It is relatively bright on our combined I-band image (we estimate I~17), and also visible on our combined R-band image, but has no obvious counterpart on the DSS2 red image. This object lies slightly outside the 2' error circle. Source #2, at RA, DEC (J2000) 02:54:19.46, 69:08:59.7, has a faint DSS2-red counterpart but is notably brighter on our R-band images than on the DSS2 red. This source lies inside the GRB error circle. Because of the telescope schedule in Tautenburg, no 2nd epoch observations can be performed by the end of July.