[vsnet-grb-info 14857] GRB 140423A: optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16171
SUBJECT: GRB 140423A: optical observations
DATE:    14/04/24 19:25:53 GMT
FROM:    K.Gaze at Nat U of Athens  <kgaze at phys.uoa.gr>

K. Gazeas  & K. Sapountzis (National University of Athens) report:

We performed photometric observations on GRB140423A (trigger 596958)
in R band (optical), using the University of Athens Observatory (0.4 m
f/8 Cassegrain Reflector, equipped with a ST10XME CCD camera).

Day/Time of observation: 23/24 April 2014, 22:20-03:00 UT (JD:
2456711.45-2456711.63)
Filters: R (Bessell)

We also conclude that the trigger is consistent with the flare star DG
CVn , although we cannot exclude the possibility of being a field GRB.
Nevertheless, photometry of DG CVn reveals significant enhancing at
the OT and subsequent fading of the flare indicating an interesting
stellar activity. The photometric variability of the DG CVn with
respect to the field standard star GSC 2003:0711, shows a gradual  
decay with a rate of 0.92 mag/hour for the first hour of observation  
after the peak (23:30-00:30 UT), followed by a decay rate of 0.34  
mag/hour for the rest 2.5 hours of observation (00:30-03:00).

[GCN OPS NOTE(25apr14):  This circular was delayed ~5 hours until
and entry in the vetted list was created.]