Buy this RX J1856 space photo. High quality Chandra picture, slide, or Duratrans backlit transparency. NASA photo RX J1856. Wide variety of sizes. RX J1856 - A compact star about 400 light years from Earth in the constellation Corona Australis. Chandra observations of RX J1856 suggest that the matter in this collapsed star is even denser than nuclear matter, the most dense matter found on Earth. X-ray and optical data indicate that RX J1856 has a diameter of only 7 miles. This size is too small to reconcile with the standard models of neutron stars. One exciting possibility is that the high density inside the star has caused the neutrons to dissolve into a soup of up, down, and strange quarks to form a strange quark star, which would have a smaller radius. April 10, 2002 Credits: NASA/SAO/CXC/J.Drake et al. CXC operated for NASA by Smithsonian Astrophysical Observatory |