[vsnet-grb-info 15212] GRB 140703A: BOOTES-2 and OSN optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16504
SUBJECT: GRB 140703A: BOOTES-2 and OSN optical observations
DATE:    14/07/03 03:30:45 GMT
FROM:    Alberto Castro-Tirado at Inst.de Astro. de Andalucia  <ajct at iaa.es>

R. Cunniffe, A. Gonzalez-Rodriguez, V. Casanova, M. Jelinek, S. Jeong, O.
Lara-Gil, S. R. Oates, R. Sanchez-Ramirez, J. C. Tello (IAA-CSIC Granada),
P. Kubanek (IP-ASCR, Prague), J. Gorosabel (IAA-CSIC, UPV-EHU) and A. J.
Castro-Tirado (IAA-CSIC, ISA-UMA), report:

Following the detection of GRB 140703A by Swift (Kocevski et al., GCNC
16503), the 0.6m TELMA robotic telescope at the BOOTES-2 astronomical
station Malaga (Spain), responded to the GRB location starting at 00:30:02
UT (i.e. 45s postburst, in the clear filter, 5s integrations). In the
longer exposures (i’-band, 60s) starting at 00:47:30 (i.e. 10 min
postburst), a faint optical source is barely detected in the images, at
the outskirts of the XRT position, which is confirmed by the 1.5m OSN
images at Sierra Nevada Observatory starting at 00:54 UT (I-band), with a
magnitude of about 20, which does not seem to be present in the DSS-2. The
preliminary position (+/- 1") is:

RA(J2000) = 00 51 59.05, Dec (J2000) = +45 06 06.

The source is detected in all optical filters. Additional observations
(imaging and spectroscopy) are ongoing.