TITLE: GCN CIRCULAR NUMBER: 9377 SUBJECT: GRB 090516: Swift/UVOT Observations DATE: 09/05/16 18:45:43 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and B. A. Rowlinson (Leicester) report on behalf of the Swift/UVOT team. The Swift/UVOT began observing the field of GRB 090516 171s after the BAT trigger (Beardmore et al., GCN Circ. 9374). Data summed from the first and second orbits does not reveal a source at the refined position of the X-ray afterglow (Beardmore et al., GCN Circ. 9376). The 3-sigma upper limits for the finding chart (fc) and summed exposures are reported below: FILTER T_start(s) T_stop Exposure Mag/3UL ============================================================= white fc 171 321 147 > 20.85 white 3843 5478 393 > 21.06 v 4254 5890 393 > 19.63 b 585 601 15 > 18.74 b 5073 5273 196 > 20.32 u 329 579 245 > 20.12 u 4868 6384 274 > 20.20 uvw1 4664 6301 393 > 20.36 uvm2 4458 6096 393 > 20.18 uvw2 4049 5685 393 > 20.41 ================================================================= The above magnitudes are not corrected for the Galactic extinction corresponding to a reddening of E_{B-V} = 0.05 (Schlegel et al., 1998, ApJS, 500, 525). The photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627).