Astronomers have observed the most massive known example of a neutron star, an object classified as a “black widow,” which has greatly increased its mass after swallowing most of the matter of a companion star with which it forms a binary star system, Reuters and Agerpres reported. on Friday.

The researchers say that this neutron star, which they found rotates on its axis 707 times per second, has a mass of about 2.35 times that of the Sun—probably the upper limit of what a star of this cosmic size can have. of the object

If the mass were greater, a black hole would form instead of a neutron star. A neutron star is the compact core of a massive star that exploded as a supernova at the end of its stellar life.

The one described by the researchers is a type of neutron star with very strong magnetic fields, called a pulsar, which emits streams of electromagnetic radiation through its poles. When the star rotates, these streams seem to pulsate, hence the name pulsar.

How neutron stars work

“The heavier the neutron star, the denser the matter inside it. This star is the most massive neutron star known and has the highest density of matter in the observable universe. If it were heavier, it would collapse in on itself and form a black hole, and then the matter inside would be beyond the event horizon, forever hidden from any possible observation,” said Roger Romani, director of the Space Center. of Sciences and Astrophysics at Stanford University, co-authored a study on this neutron star published in the Astrophysical Journal Letters.

“And since we still don’t know how matter behaves at this density, the existence of this neutron star is important evidence of these physical extremes,” he added.

This neutron star, which is in the Milky Way in the direction of the constellation Sextant, has the catalog name PSR J0952-0607 and is located about 20,000 light-years from Earth, according to Romani.

The researchers studied this neutron star using the Keck I telescope in Hawaii.

Stars with a mass of at least 8 times the mass of the Sun convert hydrogen into heavier elements through the process of fusion in their cores.

When about 1.4 solar masses of iron accumulate in the core of such a star, the star explodes as a supernova, and its core becomes superdense, becoming a neutron star—the material of such a star is so compact that a teaspoon of the material weighs more than Mount Everest.