[vsnet-grb-info 13151] GRB 130427A: Continued iTelescope T21 optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14488
SUBJECT: GRB 130427A: Continued iTelescope T21 optical observations
DATE:    13/04/28 11:37:46 GMT
FROM:    Veli-Pekka Hentunen at Taurus Hill Obs,A95  <veli-pekka.hentunen at kassiopeia.net>

Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill
Observatory, Varkaus, Finland) report:

We have continued observing GRB 130427A optical afterglow at iTelescope
observatory T21 (Mayhill, New Mexico) 0.43-m/6.8 astrograph and
FLI-PL6303E CCD. Two unfiltered, two photometric R filter and two
photometric V filter images with 600 sec exposure time were made.

The following magnitudes were obtained from the observations using
NOMAD1 1176-0248446 (R=13.520, V=13.120) as the comparison:

Tmid(h)+T0      Filter     Exp. time         Mag          Mag err. 
22.67              V              600                17.73V         0.11
22.85              V              600                17.72V         0.11
23.10              unfiltered   600                18.01CR       0.07
23.27              unfiltered   600                18.22CR       0.09
23.56              R              600                18.18R          0.12
23.74              R              600                18.36R          0.14