Recently there have been controversial claims about the nature of the isolated compact star RXJ1856.5−3754, with one group claiming it to be a strange star (Drake et al., 2002) while the other asserting it to be a normal neutron star (Walter & Lattimer, 2002). The controversy arises mainly due to the distance estimate, which in turn is used to resolve the measured angular diameter, and thus the...

Thanks to the high counting statistics provided by a recent XMM-Newton observation of RX J1856.5–3754 we have discovered that this isolated neutron star pulsates at a period of 7.055 s. This confirms that RX J1856.5–3754 is similar in nature to the other six thermally emitting, nearby neutron stars discovered in soft X–rays with ROSAT. The pulsations are detected at consistent periods in severa...

The evidence suggests that the bright soft X-ray source RXJ185635-3754 is an isolated neutron star. We have now identiied the optical counterpart. The optical and X-ray data are inconsistent with a pure blackbody, but the spectral energy distribution appears consistent with a model having sinusoidal temperature variations with latitude.

We present spectroscopy and Hα imaging of a faint nebula surrounding the X-ray bright, nearby neutron star RX J1856.5−3754. The nebula shows no strong lines other than the hydrogen Balmer lines and has a cometary-like morphology, with the apex being approximately 1′′ ahead of the neutron star, and the tail extending up to at least 25′′ behind it. We find that the current observations can be sat...

We have examined the soft X-ray plus optical/UV spectrum of the nearby isolated neutron star RX J1856 − 3754, comparing with detailed models of a thermally emitting surface. Like previous investigators, we find the spectrum is best fit by a two-temperature blackbody model. In addition, our simulations constrain the allowed viewing geometry from the observed pulse fraction upper limits. These si...