Researchers at the Green Bank Telescope in West Virginia recently discovered the largest known neutron star. The star, approximately 4,600 light years away from earth, is about five miles across. Despite being only as large as a small city, it weighs 700,000 times as much as the entirety of earth.

The new neutron star is near a larger white dwarf star. Light emitted from the newly discovered neutron star bends around the nearby white dwarf, making it take just a fraction of a second longer to reach instruments measuring it here on earth. By measuring the fraction of a second delay, researchers can extrapolate the mass of both the white dwarf star and ultimately the neutron star. The heavier the white dwarf star, the further light has to travel as it bends around it, and the longer the time delay is. Through this method, researchers determined that the new neutron star is about 2.17 times as much as the earth’s sun.

Stars this massive are interesting for two reasons. First, astronomers don’t know how heavy a star can become before it collapses into a black hole. Finding this record heavy star gives scientists a better idea of where that tipping point is. Second, with super-small and super-heavy stars, physics starts to behave in unusual ways. Instead of solids, liquids, and gases, the center of these super dense stars might have unusual forms of matter, “soups” of particles even smaller than a neutron.  Researchers are interested in using this star to study the physics in the unusual environment of its interior.

Managing Correspondent: Emily Kerr

News Articles: WVU astronomers help detect the most massive neutron star ever measured

Most Massive Neutron Star Ever Detected, Almost too massive to exist

‘Biggest’ star in the universe discovered, 700K times heavier than earth

Original Article: Relativistic Shapiro delay measurements of an extremely massive millisecond pulsar

Photo Credit: NASA