Astronomers have discovered a neutron star devouring its brown dwarf in the black widow binary system

In the context: Man has always looked at the stars. These celestial bodies fascinate even with the naked eye. However, advances in observation have made space even more intriguing. Astronomers often find astral bodies that push the boundaries of our current knowledge. The recent discovery of a binary – possibly ternary – system shows that we still have a lot to learn about how objects in our universe work.

Scientists at Caltech’s Zwicky Transient Facility (ZTF) at Palomar Observatory discovered strange pair of double stars. This is the black widow star system, designated ZTF J1406+1222. Wednesday astronomers published an article about their findings in the academic journal Nature. There are several things that make the ZTF J1406+1222 unique.

First, it’s good to know what we’re dealing with here. black widows are a rare class of binary star systems in which a dead neutron star, also known as a pulsar, orbits a hydrogen-rich star, in this case a brown dwarf. Over time, the pulsar destroys its companion by sucking material out of it and exploding it with high-intensity gamma radiation (NASA animation below).

One of the things that makes this weird is that the pulsar is moving very, very fast. While this is typical behavior for Black Widow systems, this one breaks the record with an orbital period of just over an hour at 62 minutes. The previous record holder was PSR J1653-0158, which had a sunny day of just 75 minutes. Other black widow systems run in the eight to nine hour range, which is still pretty fast.

“This 62-minute orbit is notable because we don’t understand how the stars could get into such a narrow orbit,” says Kevin Burge, lead author of the study. “The process where a pulsar destroys its companion should actually tear them apart. It pushes the boundaries of what we thought was possible.”

Black widows are very rare. They were first discovered only in the 1980s, and since then astronomers have only found a few dozen others. This turns out to be the closest we’ve seen so far, which makes it unique.

Finally, to complete the oddity, the third star appears to be gravitationally bound to the binary system, making it a triple system. This third star belongs to the class of “cold subdwarfs”. These objects have very little mass or are metals, mostly composed of hydrogen and helium.

What’s strange about this third package is that, in theory, it shouldn’t be tied to ZTF J1406+1222. It is located at about 600 AU. from a pair (one AU is the distance between the Earth and our Sun), and its low mass means that almost any stellar event should have knocked it out of orbit. Technically, the supernova formed during the formation of the ZTF J1406+1222 pulsar should have pulled it out of the gravitational hold of the system.

While ZTF J1406+1222 appears to be a new black widow, the scientists are careful to note that their results have yet to be confirmed.

“Our data shows that we are looking at a black widow binary, but it could be something completely new,” Burge said.

The team is waiting for NASA’s Chandra X-ray Observatory to confirm their findings.

Image credit: Siphon and Explosion NASA Goddard Space Flight Center