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 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.