TITLE:   GCN CIRCULAR
NUMBER:  18273
SUBJECT: GRB 150910A: Kast spectroscopy from 3m Shane telescope
DATE:    15/09/11 00:05:09 GMT
FROM:    Weikang Zheng at UC Berkeley  <weikang@berkeley.edu>

WeiKang Zheng, Alexei V. Filippenko and Heechan Yuk (UC Berkeley),
Yinan Zhu (NAOC) and Daniel A. Perley (Dark Cosmology Center)
report on behalf of the KAIT GRB team:

We observed the optical afterglow of GRB 150910A (Pagani et al., 
GCN 18264; Zheng & Filippenko, GCN 18265) with the Kast spectrograph
on the 3m Shane telescope at Lick Observatory, started at 10:08 UT
(about 1.1 hours after the burst), covering the 3500 - 10000 A   
wavelength range. A 1200-second and a 2400-second exposures
were acquired.

The spectrum shows blue continuum flux across the entire spectral
range. We detect absorption lines from Mg II (2796,2803) and Fe II
(2344,2374,2383) at a common redshift of z=1.359, as well as additional
lines further to the blue. We suggest this as the likely redshift of
the GRB.