Scientists say a very rare pair of stars is behaving ‘strange’

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A newly discovered and very rare binary star system seems to be behaving very strangely, according to the researchers who discovered it.

This system is so unusual that it is believed that there are only about 10 of them throughout our vast Milky Way galaxy.

It has all the conditions to go ahead and trigger a kilonova, or explosion that occurs when neutron stars collide, resulting in an explosion so powerful that it can be detected across the universe.

“We know that the Milky Way contains at least 100 billion stars and possibly hundreds of billions more. This remarkable binary system is essentially one system out of a whole,” said NOIRLab astronomer and co-author of the new study, André-Nicolas Chené. Ten billion.” Prior to our study, the estimate was that only one or two systems should exist in a spiral galaxy such as the Milky Way.”

The astronomers who found it say the double star system is bright in X-rays and has a high mass. But it is particularly unusual because the two stars orbit each other in what they say is a “weird circular” path.

It appears to have formed when an exploding star or supernova died down, rather than exploding with the usual dramatic explosion.

Its strange orbit helped the researchers find that one of the two stars is an “exhausted” supernova. This means that when the star has used up its fuel, and its core has collapsed, it has a relatively weak explosion.

Normally, this explosion pushes stars into a long, elliptical orbit. But there wasn’t enough energy left in the star to create such an explosion, so the two stars remained closely interconnected in a circular orbit.

Over time, they will merge, sending powerful gravitational waves through the universe and leaving behind heavy elements such as silver and gold.

The star pair is strange enough in itself. But scientists hope that finding systems like these will help us do better in the presence of kilonovae, those dramatic explanations that are also thought to be the source of gold in the universe.

“For some time, astronomers have speculated about the exact conditions that could eventually lead to a kilonova,” said Dr. Cheney. “These new results show that, in at least some cases, two sister neutron stars can merge when one was created without a classic supernova explosion.”

Known as CPD-29 2176, the system is located about 11,400 light-years from Earth. First spotted by NASA’s Neil Gehrels Swift Observatory, later observations with the SMARTS 1.5-meter telescope in Chile confirmed its unusual nature.

The findings are described in a new paper, published in Nature today, titled “High-mass X-ray binaries descended from an abstract supernova.”

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