[vsnet-grb-info 14459] GRB 140129A: P200 spectroscopy

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15773
SUBJECT: GRB 140129A: P200 spectroscopy
DATE:    14/01/30 01:58:46 GMT
FROM:    Daniel Perley at Caltech  <dperley at astro.caltech.edu>

D. A. Perley (Caltech), M. Rafelski, D. Masters (IPAC), and J. X. 
Prochaska (UCO/Lick) report:

We obtained spectroscopy of the optical afterglow of GRB 140129A 
(Melandri et al., GCN 15760) with the Double Spectrograph at the 5m 
Palomar Hale telescope beginning at 04:56:25.2 UT, approximately 1.5 
hours after the GRB trigger.  Based on our P60 imaging, the GRB 
afterglow was r~20 mag at this point and the S/N of the spectrum is low, 
although the trace is clearly detected in each of three 600s exposures. 
The spectral range covers from the atmospheric cutoff to 8700 Angstroms.

The spectrum is featureless, showing no significant absorption lines 
over our spectral range (although the EW sensitivity limit is poor). 
The absence of a DLA feature suggests a redshift of z<1.8 (more 
conservatively, the lack of IGM absorption down to the atmospheric 
cutoff indicates z<2.1).