An international team of scientists has revealed the mysterious nature of the object PSR J2039−5617. It turned out that in the center of an unknown cosmic source of X-ray and gamma radiation is a pulsar that rotates around an evaporating star. In the system, the pulsar heats up one side of the satellite star, which appears brighter and bluish. The gravitational pull of the pulsar also stretches the star, allowing astronomers to track changes in its apparent size as it rotates. The orbital period of the binary system was 5.5 hours.
Pulsar J2039−5617 rotates around its axis at a speed of 377 times per second. Its radiation vaporizes the companion, which causes clouds of charged particles to form, absorbing radio waves. It is because of this that the pulsating radio emission characteristic of the pulsar was not detected earlier, which made it difficult to determine the nature of the source.
Astronomers have known about the existence of PSR J2039−5617 since 2014, and all the data indicated that it includes a neutron star, but so far this has not been proven.