This zoomed-in image shows a neutron star emitting a comet-like wake of high-energy particles as it races through space. Astronomers think the star, known as CXOU J061705.3+222127, or J0617 for short, is moving through superheated gas that it created when it exploded as a supernova, although in an odd way.

Neutron stars found far away from the center of supernova remnants typically move radially away from the center. The wake of J0617, in contrast, appears to be moving perpendicularly toward the center.

One possible explanation for the peculiar behavior is that the neutron star is in a situation similar to comets. In our solar system, for example, no matter which way a comet is moving, whether towards or away from the Sun, it's tail will taper off in the direction away from the Sun because of the direction the solar wind blows.

If this is what's happening in the case of J0617, then observations of the neutron star with Chandra in the next 10 years should show a detectable motion away from the center of the supernova remnant.

The image is a composite made from different telescope observations: the wide-field shot was made with X-ray (blue/ROSAT & Chandra), radio (green/Very Large Array), and optical (red/Digitized Sky Survey) observations of the supernova remnant, IC 443. The closeup was taken with NASA's Chandra telescope.

-- Ker Than

Credit: Chandra X-ray: NASA/CXC/B.Gaensler et al; ROSAT X-ray: NASA/ROSAT/Asaoka & Aschenbach; Radio Wide: NRC/DRAO/D.Leahy; Radio Detail: NRAO/VLA; Optical: DSS