Astronomy Picture of the Day

    Discover the cosmos! Each day a different image or photograph of our
      fascinating universe is featured, along with a brief explanation
                    written by a professional astronomer.

                              2019 December 18

                A Hotspot Map of Neutron Star J0030's Surface
                  Image Credit: NASA, NICER, GSFC's CI Lab

   Explanation: What do neutron stars look like? Previously these
   city-sized stars were too small and too far away to resolve. Recently,
   however, the first maps of the locations and sizes of hotspots on a
   neutron star's surface have been made by carefully modeling how the
   rapid spin makes the star's X-ray brightness rise and fall. Based on a
   leading model, an illustrative map of pulsar J0030+0451's hotspots is
   pictured, with the rest of the star's surface filled in with a false
   patchy blue. J0030 spins once every 0.0049 seconds and is located about
   1000 light years away. The map was computed from data taken by NASA's
   Neutron star Interior Composition ExploreR (NICER) X-ray telescope
   attached to the International Space Station. The computed locations of
   these hotspots is surprising and not well understood. Because the
   gravitational lensing effect of neutron stars is so strong, J0300
   displays more than half of its surface toward the Earth. Studying the
   appearance of pulsars like J0030 allows accurate estimates of the
   neutron star's mass, radius, and the internal physics that keeps the
   star from imploding into a black hole.

                       Tomorrow's picture: open space
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
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                      A service of: ASD at NASA / GSFC
                             & Michigan Tech. U.

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