Chandra High Resolution Camera Imaging of Grs 1758–258

We observed the " micro-quasar " GRS 1758–258 four times with Chandra. Two HRC-I observations were made in 2000 September-October spanning an intermediate-to-hard spectral transition (identified with RXTE). Another HRC-I and an ACIS/HETG observation were made in 2001 March following a hard-to-soft transition to a very low flux state. Based on the three HRC images and the HETG zero order image, the accurate position (J2000) of the X-ray source is RA = 18 h 01 m 12 s .39, Dec = −25 • 44 ′ 36 ′′ .1 (90% confidence radius = 0 ′′ .45), consistent with the purported variable radio counterpart. All three HRC images are consistent with GRS 1758–258 being a point source, indicating that any bright jet is less than ∼1 light-month in projected length, assuming a distance of 8.5 kpc.