[vsnet-grb-info 18766] GRB 161129A: Tautenburg Ic-band observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20216
SUBJECT: GRB 161129A: Tautenburg Ic-band observations
DATE:    16/11/29 17:57:04 GMT
FROM:    Sylvio Klose at TLS Tautenburg  <klose at tls-tautenburg.de>

S. Klose and B. Stecklum (both Thueringer Landessternwarte Tautenburg) 
report:

We imaged the field of GRB 161129A (Kocevski et al., GCN 20210) with the 
Tautenburg Schmidt telescope equipped with the prime focus CCD camera. 
Observations were performed at a midtime of 16:41 UT (November 29).

Inside the enhanced XRT error circle (radius 1.7 arcsec; Beardmore et al., 
GCN 20211) we find a faint source at coordinates RA, Decl. (J2000) = 
21:04:54.53, 32:08:05.9 (+/- 0.5 arcsec). Using the USNO B2 star at 
coordinates RA, Decl. (J2000) = 21:04:54.65, 32:08:05.6 as a photometric 
reference (Ic = 18.38), we measure for this source a preliminary (Vega) 
magnitude of Ic = 20.3 +/- 0.2 mag.

We note, however, that the DSS2 red shows a faint source at the central 
position of the enhanced XRT error circle at roughly the same coordinates. 
Given that the seeing in our images is about 2 arcsec, and given that our 
images are not substantially deeper than the DSS2 red, we cannot decide 
whether we see this faint source or a faint transient on top of it. In any 
case, at the time of our observations any optical transient was fainter 
than about Ic=20.