The origin of the runaway high-mass X-ray binary HD 153919/4U1700-37

Based on its Hipparcos proper motion, we propose that the high-mass X-ray binary HD 153919/4U1700-37 originates in the OB association Sco OB1. At a distance of 1.9 kpc the space velocity of 4U1700-37 with respect to Sco OB1 is 75 km s(-1). This runaway velocity indicates that the progenitor of the compact X-ray source lost about 7 M-circle dot during the (assumed symmetric) supernova explosion. The systems kinematical age is about 2 +/- 0.5 million years which marks the date of the supernova explosion forming the compact object. The present age of Sco OB1 is less than or similar to8 Myr; its suggested core, NGC 6231, seems to be somewhat younger (similar to5 Myr) If HD 153919/4U1700-37 was born as a member of Sco OB1, this implies that the initially most massive star in the system terminated its evolution within less than or similar to6 million years, corresponding to an initial mass greater than or similar to 30 M-circle dot. With these parameters the evolution of the binary system can be constrained.