[vsnet-grb-info 14023] GRB 131014A: NOT afterglow candidate

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15337
SUBJECT: GRB 131014A: NOT afterglow candidate
DATE:    13/10/15 07:21:29 GMT
FROM:    Steve Schulze at U of Iceland  <sts30 at hi.is>

S. Schulze (PUC, MCSS), D. Xu , D. Malesani, J. P. U. Fynbo (DARK/NBI), T. Kangas (NOT), H. Ghasemi, A. Takalo, C. Xavier, Y. Litus, J. Saario, T. Tuominen, J. Harmanen, and M. Khansari (Tuorla Observatory) report on behalf of a large collaboration:

We observed the field of GRB 131014A (Fitzpatrick & Xiong, GCN15332; Desiante et al., GCN 15333) with the 2.5-m Nordic Optical Telescope (NOT) equipped with ALFOSC. We obtained 6 x 300 s R-band images. The mean time of the NOT observation is October 15.221 UT, 1.01 days after the Fermi trigger.

We detect an uncatalogued source within the error circle of the possible X-ray afterglow (Kennea et al., GCN 15335) at:

R.A.(J2000)	= 06:41:12.240
Dec. (J2000) = -19:05:51.49

with an uncertainty of 0.4''.

This source may be the optical afterglow of GRB 131014A, but we cannot presently assess its variability and thus confirm its nature. We measure a R1 magnitude of 23.11 +/- 0.12 mag calibrated against four USNO B1 stars (0709-0091487, 0708-0089714, 0709-0091459, 0709-0091432).

We also note the presence of a brighter source (R.A. = 06:41:12.1, Dec. = -19:05:47.6) just to the North of the XRT error circle, which is however detected in the SDSS r-band frames.