Tour: Eccentric 'Star' Defies Easy Explanation, NASA's Chandra Finds

Scientists have discovered a star behaving like no other seen before, giving new clues about the origin of a class of mysterious objects.

A team of astronomers combined data from NASA’s Chandra X-ray Observatory and Square Kilometer Array Pathfinder radio telescope in Australia to study the antics of the discovered object, known as ASKAP J1832 for short.

ASKAP J1832 belongs to a class of objects so-called “long period radio transients”, discovered in 2022. These vary in radio wave intensity in a regular way over tens of minutes. This is thousands of times longer than pulsars, which are rapidly spinning neutron stars that have repeated variations multiple times a second. ASKAP J1832 cycles in radio wave intensity every 44 minutes, placing it into this category of long period radio transients.

Using Chandra, the team discovered that ASKAP J1832 is also regularly varying in X-rays every 44 minutes. This is the first time that such an X-ray signal has been found in a long period radio transient.

However, that is not all ASKAP J1832 does. Using Chandra and the SKA Pathfinder, the team found that ASKAP J1832 also dropped off in X-rays and radio waves dramatically over the course of six months. This combination of the 44-minute cycle in X-rays and radio waves in addition to the months-long changes is unlike anything astronomers have seen in the Milky Way galaxy.

Scientists are now racing to figure out if ASKAP J1832 is representative of long period radio transients and whether its bizarre behavior helps unravel the origin of these objects. They have looked at several different possibilities involving neutron stars and white dwarfs, either in isolation or with companion stars. So far nothing exactly matches up, but some ideas work better than others, and the search for the truth behind this mysterious object will continue.