TITLE:   GCN CIRCULAR
NUMBER:  14070
SUBJECT: GRB 121212A: Keck observations
DATE:    12/12/12 17:24:46 GMT
FROM:    Daniel Perley at Caltech  <dperley@astro.caltech.edu>

D. A. Perley and A. Horesh (Caltech) report:

We slewed to the position of GRB121212A (rupe et al., GCN 14064) with 
the Keck I telescope (+LRIS) and acquired a series of exposures with the 
slit guider beginning at 15:40 UT, 8.7 hours after the event.

We identified a source near the DSS limit consistent with the XRT 
position, at coordinates (J2000) of:

RA  = 11:51:10.43
Dec = +78:02:15.3
(+/- 1.5 arcsec)

This is consistent with the XRT and UVOT positions (Beardmore et al., 
GCN 14066; Kuin et al., GCN 14069).

The magnitude is approximately R~21 on the guider camera at this time.

A series of 600s spectroscopic exposures were then taken during 
brightening morning twilight.

A provisional reduction of the (low S/N) spectrum shows a significant 
flux across the spectral range, extending to at least 3500 Angstroms 
with no break or strong absorption lines, suggesting z ~< 2 and 
consistent with the detection in the UVOT u filter.  Analysis is ongoing.