by Ashley Strickland, CNN
Astronomers have detected the most massive neutron star ever, and it almost shouldn’t even exist.
Neutron stars are the smallest in the universe, with a diameter comparable to the size of a city like Chicago or Atlanta. They are the leftover remnants of supernovae. But they are incredibly dense, with masses bigger than that of our sun. So think of the sun, compressed into a major city.
In the case of the newly detected neutron star, dubbed J0740+6620, it’s 333,000 times the mass of the Earth and 2.17 times the mass of the sun. But the star is only about 15 miles across. It’s 4,600 light-years from Earth.