Faculty of Science (FNWI) - Anton Pannekoek Institute for Astronomy (API)
Abstract
During a ~0.8 ksec pointed Swift/XRT observation performed on June 6, 2007 (18:26-21:38 UT), we did not detect the accreting millisecond pulsar HETE J1900.1-2455. We can set a 2-10 keV upper limit on the source flux of ~(5-15)E-14 erg/cm2/s (depending on the assumed spectral model). This is more than a factor of 10 weaker than the X-ray flux observed with Swift/XRT last week, on May 31 (ATEL #1091).