TITLE: GCN CIRCULAR NUMBER: 42228 SUBJECT: GRB 251013C: Optical Observations via Virtual Telescope Project, Italy DATE: 25/10/13 21:07:58 GMT FROM: Gianluca Masi at Virtual Telescope Project <gianluca@bellatrixobservatory.org> Gianluca Masi, Virtual Telescope Project (Italy), reports: We attempted to observe the optical counterpart of GRB 251013C (Rakotondrainibe et al., GCN 42222) with the 14” robotic unit available at the Virtual Telescope Project facility in Manciano, Italy, equipped with a KAF-3200E based CCD camera, its QE peaking (90%) in the red part of the spectrum. We collected three, 120-second unfiltered exposures, then we averaged them. The central time of the resulting stack was 13 Oct., 20:54:57 UTC, that is about 3.25 hours after the burst. We detected a bright object at the following position (J2000.0): R.A.: 23 03 20.56 Decl.: -00 13 37.1 mean residuals < 1” on both axes R= 15.9 (assuming R-mags from Gaia DR2 for the reference stars). This position is consistent with Palmerio et al. (GCN 42223)and Perez-Garcia et al., GCN 42225. View this GCN Circular online at https://gcn.nasa.gov/circulars/42228. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...