TITLE:   GCN CIRCULAR
NUMBER:  34410
SUBJECT: GRB 230812B: Spectroscopy from NOT
DATE:    23/08/14 01:51:16 GMT
FROM:    Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>

A. de Ugarte Postigo (OCA-CNRS), L. Izzo (INAF-OACN and DARK/NBI), D.B. Malesani (Radboud and DAWN/NBI), K. Matilainen (NOT) report:

We have observed the afterglow of GRB 230812B (Roberts et al. GCN34391, Scotton et al. GCN 34392, Zheng & Filippenko GCN 34395, Beardmore et al. GCN 34400) with AlFOSC, mounted on the 2.5m NOT telescope at Roque de los Muchachos Observatory in La Palma (Spain). 
We have performed spectroscopy with an exposure of 3x1200s and grism #4, with a spectral coverage between 3500 and 9600 AA. The observation started at 22:14 UT, 1.136 days after the trigger.

The spectrum shows a trace throughout the complete spectral range. In a preliminary reduction we don’t identify clear absorption features, but we do see weak detections of [OII], [OIII] and H-alpha at a redshift of z=0.360, as reported by de Ugarte Postigo et al. (GCN34409).