GCN Circular 15307
Subject
GRB131004A: Magellan Redshift
Date
2013-10-05T00:56:31Z (11 years ago)
From
Ryan Chornock at Harvard <rchornock@cfa.harvard.edu>
R. Chornock, R. Lunnan, and E. Berger (Harvard) report:
We observed the optical afterglow (Xu et al., GCN 15304; Malesani et al., GCN
15305; Kopac et al., GCN 15306) of the possible short GRB 131004A (Hagen et al.,
GCN 15303) using LDSS-3 on the 6.5-m Magellan Clay Telescope. A sequence of
3x1200s spectroscopic exposures of the afterglow began at 23:44 on 4 October UT.
A preliminary reduction reveals a flat continuum with superposed weak emission
lines from [O II], H-beta, and [O III] at a common redshift of 0.717. Possible
weak features consistent with Ca II H+K absorption at this same redshift are
also present.