TITLE: GCN CIRCULAR NUMBER: 10510 SUBJECT: GRB100316C: Swift/UVOT Upper Limits DATE: 10/03/16 20:05:15 GMT FROM: Patricia Schady at MSSL/Swift S. R. Oates (MSSL-UCL) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 100316C 81s after the BAT trigger (Stamatikos et al., GCN Circ. 10491). We do not detect any source at the enhanced Swift XRT position (Evans et al. GCN Circ. 10506). The 3-sigma upper limits for the finding chart exposures (FC) and summed images are: Filter T_start T_stop Exp(s) Mag (3-sigma upper limit) ------------------------------------------------------------- white (FC) 81 231 147 > 20.52 white 521 7450 677 > 21.63 u (FC) 239 489 246 > 19.87 u 644 7039 529 > 20.22 v 570 12991 1326 > 20.45 b 495 7245 549 > 20.72 uvw1 620 6834 333 > 20.24 uvm2 595 13530 741 > 20.60 uvw2 546 7656 471 > 20.57 ------------------------------------------------------------- The quoted upper limits have not been corrected for the expected Galactic extinction along the line of sight of E_(B-V) = 0.04 mag. All photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627).