The Orbit of the High-Mass X-Ray Binary Pulsar 1E1145.1-6141

Observations of the 297 s X-ray pulsar 1E1145.1-6141 with the Rossi X-Ray Timing Explorer have revealed its 14.4 d eccentric orbit around its B supergiant companion. The best-fit orbital elements are: P_orb = 14.365(2) d, a_x sin i=99.4(18) light-s, e=0.20(3). No eclipses are detected, indicating that the binary inclination is less than 55 deg.