TITLE:   GCN CIRCULAR
NUMBER:  16985
SUBJECT: GRB 141028A: LCOGTN observations
DATE:    14/10/29 11:39:20 GMT
FROM:    Drejc Kopac at Math Phys U,Slovenia  <drejc.kopac@fmf.uni-lj.si>

D. Kopac (LJMU), J. Japelj (U. Ljubljana), C. Guidorzi (U. Ferrara), C. 
Mundell (LJMU), S. Dichiara (U. Ferrara), on behalf of a large 
collaboration report:

Using the Las Cumbres Observatory Global Telescope Network (LCOGTN) we 
observed the field of Fermi GRB 141028A (Bissaldi et al., GCN 16969; 
Roberts, GCN 16971). Optical observations in r' and i' filters (5 x 120s 
sequences) were obtained with 1-m telescopes in Sutherland (South 
Africa) and Cerro Tololo (Chile).

At the position of the MASTER telescope detection (Gorbovskoy et al., 
GCN 16972) we detect an un-catalogued source, consistent with GROND 
(Graham et al., 16977), UVOT (Siegel et al., GCN 16979) and RATIR 
detections (Troja et al., GCN 16980). Our preliminary photometry yields:

Mid time from   Total Exp   Filter   Magnitude
trigger (hr)    (s)
-------------------------------------------------
10.2            600         r'       19.4 +- 0.1
10.6            960         i'       19.3 +- 0.2

14.9            600         i'       19.9 +- 0.2
------------------------------------------------

The magnitudes are calibrated against nearby SDSS stars and are not 
corrected for the Galactic foreground extinction. Further observations 
with the LCOGTN are scheduled.