[vsnet-grb-info 15857] GRB141121A: Discovery Channel Telescope Optical Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17145
SUBJECT: GRB141121A: Discovery Channel Telescope Optical Observations
DATE:    14/12/07 21:48:55 GMT
FROM:    Vicki Toy at UMD  <vtoy at astro.umd.edu>

V. Toy (UMD), J. Capone (UMD), A. Cucchiara (NASA-GSFC), S.B. Cenko
(NASA-GSFC), E. Troja (NASA-GSFC), A. Kutyrev (NASA-GSFC), and S. Veilleux
(UMD) report on behalf of a larger collaboration:

We observed the field of GRB141121A (Swift trigger 619182, Lien et al., GCN
17075) with the Large Monolithic Imager (LMI) on the 4.3m Discovery Channel
Telescope (DCT) at Happy Jack, AZ from 2014/12/07 6:44 to 2014/12/07 11:01
UTC (starting 386.1 hours after the Swift trigger). A source is clearly
detected at the location of the optical afterglow in g', r', i', and z'.
Using nearby point sources from SDSS R8 for calibration we measure i' =
23.26 +/- 0.12.

This magnitude is reported in AB magnitude and is not corrected for
Galactic extinction in the direction of the GRB.

Compared to RATIR observations on 12/01 (Watson, GCN 17128) the afterglow
has steepened to a decay index of ~ t^-2.1.  At this time we cannot confirm
if this is the host galaxy.  Further observations are planned.

We thank the staff of the Discovery Channel Telescope for assistance with
these observations.