[vsnet-grb-info 1769] GRB 050714, optical observations

[GCN Circulars]

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  <klose at tls-tautenburg.de>

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.