An unresolved X - ray source inside the supernova remnant RCW 86

We report on the discovery of an unresolved X-ray source inside the supernova remnant G315.4-2.3 (RCW 86). The source is located 7 to the Southwest of the geometrical centre and may be close to the actual explosion centre of the supernova, which makes this a candidate for the stellar remnant associated with RCW 86. However, the presence of a possible optical counterpart with V ∼ 14 at 3 from the X-ray position and evidence for long term variability means that the source is probably an active star. A better X-ray position and better X-ray spectroscopy along with an identification of the optical source are needed to exclude the X-ray source as a neutron star candidate.