[vsnet-grb-info 13259] GRB 130427A: Amateur observations from Sweden

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14596
SUBJECT: GRB 130427A: Amateur observations from Sweden
DATE:    13/05/07 19:05:46 GMT
FROM:    Lars Hermansson at Uppsala Amateur Astronomers  <lars.hermansson4 at comhem.se>

L. Hermansson, P. Holmström, M. Johansson (Sandvreten Observatory, Sweden)

We observed the field of GRB 130427A (Maselli et al., GCN 14448; Elenin et
al., GCN 14450) with the 0.45 m f/4.5 Newton located at Sandvreten
Observatory, Sweden.

Observations were obtained between 2013-Apr-27 22:29:03 and 23:48:43 UT. Two
images each were obtained in each of B, V, Rc and Ic bands with Schüler
Johnson-Cousins photometric filters and an SBIG ST-7E CCD.

The following magnitudes were obtained from the observations with Maxim DL
software using four SDSS comparison stars transformed to the BVRI system
using Lupton (2005). Magnitudes are not corrected for extinction.

Filter    Tmid (T0+day)   Exp (s)    Mag         Err
B         0.65231         2x600      17.74       0.06
V         0.63317         2x300      17.38       0.03
Rc        0.61726         2x300      16.99       0.03
Ic        0.66821         2x300      16.78       0.05

We wish to thank D. A. Kann and the Cosmoquest forum for alerting us to GRB
130427A. We are also grateful for the guidance D.A. Kann provided during the
preparation of this report.