[vsnet-grb-info 13331] GRB 130515A: FORS2 spectroscopy of candidate counterpart

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14667
SUBJECT: GRB 130515A: FORS2 spectroscopy of candidate counterpart
DATE:    13/05/16 09:04:17 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3 at star.le.ac.uk>

A. J. Levan (U. Warwick)  and N. R. Tanvir (U. Leicester) report for a larger collaboration:

We observed the location of GRB 130515A (Malesani et al. GCN 14650) with VLT/FORS2, beginning at ~03:30 UT, 2 hours after the burst. At this epoch we obtained imaging and spectroscopy of the brightest source in the XRT error box (S1 in Xu et al. GCN 14653 and Cenko et al. GCN 14656). This spectrum exhibits several broad absorption features consistent with an M-dwarf star at z=0, indicating that it is not the host galaxy of GRB 130515A.

In fact, preliminary analysis of our imaging suggests that sources S2 and S3 referred to by Xu et al. and Cenko et al. are also consistent with being point-like.  The nearest evidently extended, and reasonably bright, source is a galaxy at position 18:53:45.01  -54:16:50.9, approximately 8 arcsec from the current enhanced X-ray position (http://www.swift.ac.uk/xrt_positions/00555880/).

We thank the staff at Paranal for their excellent support with these observations.