TITLE:   GCN CIRCULAR
NUMBER:  11230
SUBJECT: GRB 100906A: Gemini-N/GMOS redshift
DATE:    10/09/06 15:15:39 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

N. R. Tanvir, K. Wiersema (U. Leicester) and A. J. Levan (U. Warwick)
report on behalf of a larger collaboration:

We observed the location of GRB 100906A (Markwardt et al. GCN 11227;
Ivanov et al. GCN 11228; Melandri et al. GCN 11229) with
the Gemini-North Telescope on Mauna Kea using the GMOS spectrograph.
Observations began at 14:30 UT, approximately 40 minutes post burst.

We detect strong continuum from the afterglow, and identify numerous
absorption lines, including CIV (1458, 1551A), FeII (2344, 2374, 2383A)
at a common redshift of z=1.727.

Further analysis is ongoing.

We acknowledge the support of Chad Trujillo in obtaining these observations.