TITLE: GCN CIRCULAR NUMBER: 9981 SUBJECT: GRB 090929A: Swift/UVOT Observations DATE: 09/09/30 22:34:16 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and K. L. Page (U. Leicester) report on behalf of the Swift/UVOT team. Swift/UVOT began settled observations of GRB 090929A about 13 hours after the burst (Rau, GCN Circ. 9962; Cummings & Krimm, GCN Circ. 9966; Golenetskii et al., GCN Circ. 9968; Page, GCN Circ 9977). Due to the presence of a 9th magnitude (V) star 45" from the center of the BAT position, data were only obtained in the UVM2 filter. We do not detect any uncatalogued UV source within the BAT error circle. The 3-sigma upper limit and summed exposure is reported below: FILTER T_start(s) T_stop Exposure Mag/3UL ============================================================= UVM2 47411 52924 2252 >21.26 ============================================================= This magnitude is not corrected for the Galactic extinction corresponding to a reddening of E_{B-V} = 0.07 (Schlegel et al., 1998, ApJS, 500, 525). The photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627).