SUBJECT: GRB 160131A: RATIR Optical Observations DATE: 16/01/31 13:36:58 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM
We detect a bright uncatalogued source at 05:12:40.33 -07:03:00 (J2000, ±0.5 arcsec). In comparison with the USNO-B1 catalog, we obtain the following mean magnitudes: r = 13.35 ± 0.04 i = 13.01 ± 0.02 z = 12.67 ± 0.04 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB.
The source fades roughly as t^-0.87 during our observations. This source is presumably the optical counterpart reported by Page et al. (GCN Circular 18951), Yurkov et al. (GCN Circular 18952), Guidorzi et al. (GCN Circular 18953), and Xin et al. (GCN Circular 18954).
SUBJECT: GRB 160131A: GTC spectroscopy of the afterglow DATE: 16/01/31 23:49:42 GMT FROM: Antonio de Ugarte Postigo at IAA-CSIC
In spite of the poor seeing we detect a strong continuum across the complete range with multiple absorption features of FeII, NiII, MnII, MgII, MgI, and CaII at a common redshift of 0.972, consistent with the value measured by Malesani et al. from TNG (GCN 18965).