Scientists from the National Astronomical Observatory of the Chinese Academy of Sciences (NAOC), together with their international partners, detected the dual pulsar system with an orbital period of 53 minutes using the 500-meter Spherical Radio Telescope (FAST). Known as PSR J1953+1844 or M71E, this newly discovered system fills a pre-existing gap in our understanding of the evolutionary stages of spider pulsar systems.

The findings were recently published in a journal Nature .

The first pulsar was discovered in 1967. About 3,000 of these fascinating objects have now been found, spinning regularly and rapidly like spirals in the sky.

Some pulsars exist in binary systems orbiting their companion stars. If the two stars are close together, the pulsar will swallow material from the companion star to continue spinning. Initially, the accompanying star is heavy. But when a pulsar “eats” its companion star, the two stars converge and spin against each other at increasing speed. Conversely, as the star loses mass and becomes lighter, the pulsar cannot continue to loot and therefore pushes away its companion star. As a result, the orbital velocity of the pulsar slows down.

This behavior, reminiscent of female spiders eating male spiders, inspired astronomers to name objects in these two stages after red and black widow spiders, respectively. They are known collectively as spider pulsars.

Evolution from redback to black widow takes a long time, up to hundreds of millions of years. Previously, only binary pulsar systems in the red ridge and black widow states have been detected, and no intermediate states have yet been found. This creates observational problems because the orbital period of the intermediate pulsar predicted by this theory is very short and the distance between the two stars is very close. Therefore, the theory of evolution of spider pulsar systems from red cross to black widow has not been fully proven.

But the possibility of this evolutionary path has now been confirmed by FAST, the world’s largest and most sensitive radio telescope. Using FAST’s long-term observations, the research team discovered a spider pulsar system with the shortest rotation time ever discovered (just 53 minutes). Based on various indications during the observation, the researchers determined that the system is in an intermediate state on the evolutionary path from the red ridge to the black widow, thus filling the missing link in the theory of spider pulsar evolution.

“The binary system’s orbit is almost face-to-face; such a system is extremely rare. Using its extremely high detection capabilities, FAST found it in a vast sea of ​​stars. This filled a gap in the evolution of spider pulsar systems and represents unprecedented precision. [FAST]” said JIANG Peng of NAOC, co-author of the study.

nature critics described the result as “a very interesting binary pulsar system.” This discovery cuts the record for the shortest orbital period of the binary pulsar system by about 30%; This points to a new and unknown process in the evolution of spider pulsars.”