TITLE:   GCN CIRCULAR
NUMBER:  16367
SUBJECT: GRB140606B/iPTF14bfu: Discovery Channel Telescope Optical Detection
DATE:    14/06/08 18:57:35 GMT
FROM:    Vicki Toy at UMD  <vtoy@astro.umd.edu>

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

We observed the field of GRB140606B/iPTF14bfu (Singer et al., GCN 16360,
Fermi 432717114, Burns et al. GCN 16363) with the Large Monolithic Imager
(LMI) on the 4.3m Discovery Channel Telescope (DCT) at Happy Jack, AZ from
2014/06/08 9:05 to 2014/06/08 09:41 UTC (starting 29.9 hours after the
Fermi trigger).  A source is clearly detected at the location of the
optical afterglow in g', r', i', and z'.  Using nearby point sources from
APASS for calibration we obtain the following detections:

g' = 22.8 +/- 0.04
r' = 22.2 +/- 0.04
i' = 22.1 +/- 0.05
z' = 22.1 +/- 0.08

These magnitudes are reported in the AB system and are not corrected for
Galactic extinction in the direction of the GRB.  Further observations are
planned.

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