Revisiting the parallax of the isolated neutron star RX J185635-3754 using HST/ACS imaging

Abstract

We have redetermined the parallax and proper motion of the nearby isolated neutron star RX J185635-3754. We used eight observations with the high-resolution camera of the HST/ACS taken from 2002 through 2004. We performed the astrometric fitting using five independent methods, all of which yielded consistent results. The mean estimate of the parallax, 8.16+0.9-0.8 mas (1σ), corresponds to a distance of 123 +011-15 pc, in good agreement with our earlier published determination.