NASA's NICER Instrument Delivers Best-Ever Pulsar Measurements

NASA has announced that it has taken some new measurements of a Pulsar using the NASA Neutron star Interior Composition Explorer or NICER. That instrument is an x-ray telescope that is aboard the ISS.

Scientists have used NICER to obtain the first precise and dependable measurements of both a pulsar's size and mass as well as the first map of hotspots on its surface. The pulsar that NASA has measured is J0030+0451, known as J0030 for short. It's in an isolated region of space about 1,100 light-years away in the constellation Pisces.

While NICER measured the heft and proportions of the pulsar, it revealed that the shapes and locations of million-degree hot spots on the surface of the Pulsar are stranger than initially thought. The team found that J0030 revolves 205 times per second. Observations from July 2017 to December 2018 allowed two groups of scientists to map hot spots using independent methods and converge on similar results for mass and size.

One group found that the pulsar is around 1.3 times the mass of the Sun and only 15.8 miles across. The second team determined that the pulsar is about 1.4 times the Sun's mass and 16.3 miles wide. A pulsar is so dense that the gravity it creates warps nearby space-time the way a bowling ball on a trampoline would stretch the surface.

The team says that the distortion from the bending of space-time is bent and redirected in our view, making the star look larger than it is. The observations revealed the hot spots to include one that is small and circular and another that is long and crescent-shaped. Theoretical predictions suggested that the hot spot locations and shapes could vary. This study is the first to map these surface features.