There are plenty of types of stars out there, but one stands out for being just a little weirder than the others.
You might even say it’s strange.
According to a paper from researchers at Guangxi University in China, the birth of one might have recently been observed for the very first time.
A strange star is a (so far theoretical) compact star that is so dense it literally breaks down regular parts of atoms (like neutrons) into their constituent quarks.
Moreover, even those quarks (the up and down that comprise a neutron) get compressed into an even rarer type of quark called a strange quark – hence the name strange star.
Technically, the “strange” matter that a strange star would be composed of is a combination of up, down, and strange quarks.
But, at least in theory, this mix of sub-hadronic particles could even be more stable than a traditional neutron star, which is similar to a strange star but doesn’t have enough gravity to break down the neutrons.
Strange stars, though they exist in theory, are exceedingly rare. No one has ever proven that one exists. But Xiao Tian and his co-authors think they might have found evidence of one.
Their paper describes a recent gamma-ray burst known as GRB 240529A that they think holds the clues to finding a strange star.
Gamma-ray bursts, the gigantic implosions that sometimes result from creating a black hole, could also have other causes – or “central engines,” as they are called in the literature. One such central engine is the creation of a magnetar.
Magnetars are another type of neutron star that is even more extreme. Their magnetic fields could be up to 1,000 times that of a typical neutron star, giving them the largest magnetic fields in the known universe. In them, electrons and protons are forced together to create neutrons, hence the name neutron star.
However, they could also collapse upon themselves, as a part of cosmological theory allows for a magnetar to collapse into an even more dense form, which would be something akin to a strange star with the requisite mix of quarks.
Doing so would undoubtedly produce a gamma-ray burst, which Dr. Tian and his co-authors believe they found in GRB 240529A.
The details of that particular GRB hold the clues. There were three distinct “emission episodes” that represented different phases of the collapse to a magnetar, then to a strange star, and then the spin-down of the strange star.
A different spectrum of gamma rays represents each as part of the burst, and each episode was separated by a few hundred seconds of relative calm, which seems like an exceedingly short time considering how massive the objects were collapsing.
Moreover, in the X-ray spectrum, another part of the light curve could be described as containing “plateaus.” According to the authors, each of these plateaus could represent a stage in the birth of the strange star, with the first representing its cooling and the second representing its “pin down” phase.
According to their calculations, the observed data best matches the theoretical values that would be seen if GRB represented the birth of a strange star. So it seems likely that, for the first time, astronomers have garnered some evidence to support a theory that was initially developed in the 1980s.
But, as always, more testing is needed, and other researchers should confirm the authors’ calculations. But if they do, it would be a significant leap forward in experimental astrophysics – and may herald many more strange findings to come.
Written by Andy Tomaswick/Universe Today.
