TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3230 SUBJECT: GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT DATE: 05/04/11 02:50:36 GMT FROM: Stephen Holland at USRA/NASA/GSFC/SSC P. Boyd (GSFC-UMBC), S. T. Holland, M. Still (GSFC-USRA), V. Mangano (INAF-IASF/Palermo), S. Hunsberger, (PSU), T. Poole (MSSL), N. Gehrels (GSFC), K. Mason (MSSL), J. Nousek (PSU), and A. Wells (Leicester) on behalf of the Swift UVOT team report: The Swift Ultraviolet/Optical Telescope (UVOT) observed the field of GRB 050410 (Fenimore et al., GCN 3219) starting at 12:46:04 UT on 10 April 2005. We find no evidence for a source in the 5 arcsecond radius XRT error circle (La Parola et al., GCN 3218) in the UVOT data. The 3-sigma limiting magnitudes in a 3.5 arcsecond radius circular aperture , and the coadded exposure times, are: V = 19.9 (392 s), B = 21.2 (1199 s), U = 20.9 (1326 s), UVW1 = 20.8 (399 s), UVM2 = 21.1 (399 s), and UVW2 = 21.7 (788 s). The magnitudes reported in this Circular are based upon preliminary flight calibrations.