Abstract
We have obtained a Swift TOO observation of the millisecond X-ray pulsar HETE J1900.1-2455 on 2005 June 29 UT 21:36:06 for about 900s. The X-ray Telescope (XRT) observation was done in Photon Counting (imaging) mode. The source is clearly detected with significant pile-up. The bright point source is located at R.A.=19:00:08.4, Decl.=-24:55:16. We estimated an uncertainty of 5 arcsec. The millisecond X-ray pulsar is the only X-ray source in the field of view of the XRT.