[vsnet-grb-info 15882] GRB 141212A: extended object within the XRT error circle

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17170
SUBJECT: GRB 141212A: extended object within the XRT error circle
DATE:    14/12/12 22:18:17 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani at dark-cosmology.dk>

D. Malesani (DARK/NBI), P. D'Avanzo (INAF/OABr), V. D'Elia (INAF/OAR and 
ASI/ASDC), S. D. Vergani (CNRS/GEPI), G. Andreuzzi (INAF/TNG), A. Garcia 
de Gurtubai Escudero (INAF/TNG), A. Bonomo (INAF/OATo), report on behalf 
of the CIBO collaboration:

We observed the field of GRB 141212A (Ukwatta et al., GCN 17158) using 
the TNG optical telescope located in La Palma. Observations started on 
2014 Dec 12.832 UT (7.73 hr after the GRB) and consisted of 10x240 s in 
the R band. The PSF in our image was around 1.5".

Within the XRT error circle (Osborne et al., GCN 17164; see also 
http://www.swift.ac.uk/xrt_positions/), we detect a single, extended 
object (A), with coordinates (J2000):

RA = 02:36:29.95
Dec = +18:08:47.2

Its Vega magnitude is R = 22.66 +- 0.23, assuming R = 16.83 for the USNO 
star at RA = 02:36:35.95, Dec = +18:09:16.8.

We cannot yet make any claim about variability, so the connection of 
this object with GRB 141212A is unclear. This may be the GRB host, 
though some contribution from an afterglow cannot be excluded.

We also note the presence of two extended objects just outside the XRT 
error circle.

(B): RA = 02:36:30.25, Dec = +18:08:50.1, R = 22.29 +- 0.16;
(C): RA = 02:36:29.64, Dec = +18:08:50.2, R ~ 24.0

Object (C) is barely detected. No other sources are visibile in the 
proximity of the XRT error circle down to a limiting magnitude of R = 24.

A finding chart can be seen at the following URL: 
http://www.astro.ku.dk/~malesani/GRB/141212A/GRB141212A_TNG.jpg