TITLE: GCN CIRCULAR NUMBER: 14617 SUBJECT: GRB 130427A: host galaxy observations DATE: 13/05/09 20:03:02 GMT FROM: Klaas Wiersema at U Leicester K. Wiersema (U. of Leicester), O. Vaduvescu (ING), N. Tanvir (U. of Leicester), A. Levan (Warwick) and O. Hartoog (U. of Amsterdam) report: We observed the position of GRB 130427A with the 4.2m William Herschel telescope, using the PFIP camera, on May 8th, under good seeing conditions (0.7 arcseconds). Exposures of 4x600 seconds were obtained using a narrowband filter covering the [O II] emission line doublet (3728 A) at the redshift of the GRB (z=0.3399; Levan et al., Xu et al. and Flores et al.; GCN 14455, 14478, 14491). We used this filter to obtain the best visibility of the host galaxy against the bright afterglow and possible supernova contribution. The resulting data show a clear detection of the host galaxy. The GRB is located near, but somewhat offset from, a brighter patch in the host. The host is an irregular galaxy, with a broadly elliptical shape. The GRB is located North-West of the majority of extended, smooth, host emission - a convenient choice in spectrograph slit position angle may minimize host contamination and aid in identification of SN signatures. The long axis of the host is approximately oriented along 70 degrees position angle (where North=0, East = 90 degrees), and is approximately 3.4 arcseconds in length. A jpg finder chart of the [OII] imaging can be found here: http://www.star.le.ac.uk/~kw113/grb130427A/hostgalaxy_130427a.jpg [GCN OPS NOTE(09may13): Per author's request, the "Apr 8" was changed to "May 8" in the first sentence.]