Astrophysicists at Moscow State University have published the results of a study of a neutron star called XB091D. This star is the slowest pulsar, which gradually "rejuvenates", increasing its rotation speed.
A pulsar is a superdense neutron star rotating around its axis up to a hundred times per second. Their radio emission can be directed to the Earth, but it is not constant due to rapid rotation, a pulsation effect is created. From this came the name of the stars.
Slowest pulsar
Scientists from the Sternberg State Astronomical Institute at Moscow State University and their colleagues from Italy and France have recorded a rare phenomenon. They watched the slowest pulsar, XB091D, gradually increase its rotation speed. Now it is a complete revolution every 1.2 seconds. In 50 thousand years, it will become an "ordinary" pulsar with a rotation speed of once per millisecond.
XB091D is about 1 million years old. A small star helps it unwind, 20% less than the Sun in mass. The pulsar is located at a distance of 2.5 million light years from the Earth, this is a big problem for studying the radio emission of a star: only 12 photons are visible per minute, and it took 50 billion to study.
In our Galaxy, none of the one and a half hundred globular clusters has such slow X-ray pulsars. This suggests that the extremely densely packed core in the B091D cluster is much larger than that of the normal cluster. This means that we are dealing with a larger and rather rare object - with the dense remnant of a small galaxy that was once swallowed up by the Andromeda galaxy. The density of stars here is about ten million times higher than in the vicinity of the Sun, and this region stretches for about 2.5 light years.
Infographics: A. Zolotova
Promotional video:
Ivan Zolotukhin. Researcher at the Moscow State University