Jets of particles radiating x-rays are typically associated with black holes, but NASA astronomers say they have found an x-ray jet [artist's conception above] streaming from the neutron star Cir X-1 in the constellation Circinus , 20,000 light-years away. The result suggests that x-ray jets result from the strong gravity of collapsed stars, rather than properties of a black hole such as the event horizon, according to a report to appear in an upcoming issue of The Astrophysical Journal Letters. Researchers believe jets consist of accelerated cosmic material that fell too close to a black hole or, in this case, a neutron star.