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 b inary HD 153919/4U1700-37 originates in the OB association Sco OB1. At a di stance of 1.9 kpc the space velocity of 4U1700-37 with respect to Sco OB1 i s 75 km s(-1). This runaway velocity indicates that the progenitor of the c ompact X-ray source lost about 7 M-circle dot during the (assumed symmetric ) supernova explosion. The systems kinematical age is about 2 +/- 0.5 milli on years which marks the date of the supernova explosion forming the compac t object. The present age of Sco OB1 is less than or similar to8 Myr; its s uggested 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 l ess than or similar to6 million years, corresponding to an initial mass gre ater than or similar to 30 M-circle dot. With these parameters the evolutio n of the binary system can be constrained.