TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3161 SUBJECT: GRB 050401: Prompt XRT position DATE: 05/04/01 15:09:18 GMT FROM: David Burrows at PSU/Swift L. Angelini (GSFC), J. L. Racusin, S. Hunsberger, D. N. Burrows, J. E. Hill, J. A. Kennea, D. C. Morris, D. Grupe, J. A. Nousek (PSU), J. P. Osborne, K. L. Page, M. R. Goad, A. P. Beardmore, O. Godet, A. F. Abbey, A. A. Wells (U. Leicester), S. Campana, A. Moretti, C. Pagani, P. Romano, G. Tagliaferri, G. Chincarini (INAF-OAB), G. Cusumano, V. La Parola, V. Mangano, T. Mineo (INAF-IASF/Palermo), P. Giommi, M. Capalbi, M. Perri, F. Tamburelli (ASDC), F. Marshall, N. White, N. Gehrels (GSFC), P. Roming, P. Meszaros (PSU), P. Schady (MSSL), report on behalf of the Swift XRT team: The Swift BAT instrument triggered on GRB050401 at 14:20:15 UT and Swift executed a prompt slew (delayed by 9 seconds due to an Earth constraint) . The XRT found a bright source located at the following position (based on 38 counts in 2.5 seconds): RA(J2000) = +16h 31m 29s, Dec(J2000) = +02d 11' 14" We estimate an uncertainty of about 6 arcseconds. This source is located 42 arcseconds from the BAT position. We note that Swift had a solid attitude solution during this observation. The XRT reported a prompt raw spectrum that peaks at about 1 keV with a roughly power-law shape (based on 328 s of data in Windowed Timing mode).