Does our sun have a long lost twin?

The strange configuration of the material in the far reaches of our solar system has led a team of scientists to speculate that the Sun had a companion in his early days. Curiously, this scenario could explain the presence of the hypothesis Planet Nine, should it exist.

The hypothetical twin of our Sun is long gone, but traces of it can be seen in the glut of material located in the outer Oort cloud, according to new research published in The Astrophysical Journal Letters.

The Oort Cloud is the most remote region in the solar system, residing FAother than the outer planets and the Kuiper Belt. Unlike the Kuiper Belt, which is shaped like a donut, the Oort Cloud is a massive, thick spherical shell that envelops the entire solar system. The inner Oort cloud begins about 1000 AU from the Sun (where 1 AU is the average distance of Earth to the Sun), while its outer edge stops at around 100,000 AU.

This region of space is filled with billions, perhaps billions of rocky and icy objects left over from the formation of the solar system. According to the new paper, the overabundance of matter assumed to exist in the outer Oort cloud is the result of our Sun’s first passage as a binary system.

To date, computers trying to simulate the formation of the solar system have failed to replicate the proportion of objects seen in the outer realms of the Oort Cloud and the Scattered Disk – a specific population of trans-Neptunian objects. outside the Kuiper Belt. As a result, the origin of the outer Oort cloud is “an unsolved mystery,” according to the article, written by astronomers Avi Loeb and Amir Siraj of the Center for Astrophysics at Harvard and Smithsonian.

The new paper presents an elegant solution to the overpopulation problem: a second sun.

“A stellar companion of the Sun would increase the chances of trapping objects from the Sun birth cluster,” Loeb wrote in an email. “The Sun and its companion act like a fishing net that traps objects by gravity as they pass close to one of the two stars and lose energy when hitting it lightly.

By birth cluster, Loeb refers to a cluster of stars that arose together in the same molecular cloud, also known as the stellar nursery.. Star clusters end up dispersing, either because strong stellar winds or tidal gravitational forces exerted by the Milky Way galaxy itself. the Sun’s supposed twin would have been pulled far, far away a way.

“Popular theory associates the origin of the Oort cloud with debris left by the formation of the solar system, ”Loeb said. “The objects were scattered by the planets over great distances. But this model struggles to reproduce the observed relationship between the population of scattered discs of objects and the more spherical Oort cloud. Our model can explain this ratio. “

The hypothetical second sun, to trap this excess matter, would require a mass comparable to our own Sun. So, basically a twin. The two stars would have been about 1000 AU apart, according to the new model.

“It is quite plausible that the Sun could have started its life as a binary system”, Konstantin Batygin, a professor of planetary science at the California Institute of Technology who was not involved in the new study, said in an email. “In fact, observations of young star clusters suggest that a very large fraction of stars similar to the sun are born in multiples, which dissociate later.

Large amounts of celestial matter would have been lost when the two stars separated, but the authors claim that there was enough material left to explain the Oort cloud. The stars passing through the birth cluster were probably responsible for the separation of the Sa die its alleged companion, but not before our solar system captures its population of external objects, namely the Oort Cloud and – most likely – the elusive Planet nine. This gigantic hypothetical planet, to describeed by Batygin and his Caltech colleague Mike Brown in 2016, it is believed to exist in the outer solar system due to the particular aggregation of certain Kuiper Belts objects.

An ongoing origin story for Planet Nine is that it formed as a gas giant in the inner solar system, but was pushed into the outer solar system after getting too close to Jupiter. The new document offers an alternative scenario: planet nine has been captured by our solar system.

“The training puzzle involves not only the Oort clouds, but also the extreme trans-Neptunian objects, like the potential Planet Nine,” Loeb said. “We don’t know where they come from, and our model predicts that there should be more objects with an orbital orientation similar to that of planet nine.

Indeed, Planet Nine could be a ninth literal planet or an entire population of dwarf planets, or even a massive ring of debris.

“Siraj and Loeb have come up with a new idea for the early history of our solar system and give an interesting new insight into the possible origins of the hypothetical Planet Nine”, James Unwin, a physicist at the University of Illinois at Chicago who is not affiliated with the new research, said in an email. “It is worth noting that the authors present a testable hypothesis in the form of an overabundance of dwarf planets, and it will certainly be interesting to see if this is confirmed in future observations.

The upcoming Vera C. Rubin observatory, scheduled to open in 2021, has the potential to prove or disprove the existence of Planet Nine. As for finding our Sun’s long-lost twin, that could be extremely difficult. As Siraj noted in a Harvard & Smithsonian Press release, this desperate star “could now be anywhere in the Milky Way.”

Shame. But seriously, how cool would it be to find the closest sibling to our Sun?