TITLE: GCN CIRCULAR NUMBER: 10433 SUBJECT: GRB 100219A: Pre-explosion imaging and host candidate DATE: 10/02/19 17:55:52 GMT FROM: Josh Bloom at UC Berkeley J. S. Bloom (UC Berkeley) and P. E. Nugent (LBNL) report: "We co-added 27 archival images from the DeepSky* project at Palomar Observatory covering the field of GRB 100219A (Rowlinson et al. 2010, GCN Circ. 10430). The images were obtained between 2004-2007 from the Palomar-Quest Consortium at the Oschin Schmidt telescope. The limiting magnitude of the stack is approximately R ~ 22.5 mag. In the combined image we detect a faint (R = 21.0 +/- 0.3 mag relative to nearby USNO catalog stars) slightly extended source, outside the current XRT error circle to the North by ~3.7". The approximate (+/- 1") coordinates of the source are: RA = 10:16:48.52, DEC = -12:33:57.5 (J2000) Within the errors, this is coincident with the UVOT source reported by Holland et al. (GCN 10432). This is a potential (lowish redshift) host candidate of the event and we encourage spectroscopic follow-up." * http://supernova.lbl.gov/~nugent/deepsky.html