How scientists found an unexplained star in space Astronomy

How scientists found an unexplained star in space

The pulsar, called PSR J0908-4913 (abbreviated J0908), suddenly changed the speed of its rotation. This happens with pulsars, and the failure of the rotational speed itself is called a glitch.

It is quite remarkable that the Parkes radio telescope has been observing this pulsar for more than 20 years without recording a single failure," says astrophysicist Marcus Lower from Swinburne University of Technology in Australia.

Pulsars are a rapidly rotating dead star, also called a neutron star. In fact, it is the core that remains after a star of a certain mass has passed the supernova stage. Pulsars are distinguished by powerful radiation emanating from the poles. At the same time, they rotate at high speed and look like some kind of space beacons.

Since the rotation speed of pulsars is constant, the blinking produced by them is characterized by accuracy and rhythmicity, being a useful tool for astronomers. But of the approximately 2,700 known pulsars of the Milky Way, rotation failures are observed only in a small percentage (5-7%). At the same time, the rotation speed increases, and it is believed that this effect is caused by processes inside a neutron star.

The pulsar J0908 has a 107-millisecond rotation period. It was discovered in 1988 using the Molonglo Observatory Telescope (MOST). Subsequent observations of him were conducted for more than two decades. The glitch in question was recorded on October 9, 2019.

J0908 is what radio astronomers call a "young pulsar", subject to the greatest number of glitches and having unstable rotation periods that can range from tens to hundreds of milliseconds over several years, explains Marcus Lower.

Pulsars, as a rule, change the rotation speed every 6-25 years. It is likely that J0908 has already failed many times and, perhaps, long-term monitoring began immediately after the next failure.

It may take years before J0908 crashes again. But until then, there is a lot to learn about it: whether the pulsar will show any oddities after the failure, how long it will take it to return to normal, and whether the failure caused any long-term changes.