Does our sun have a long lost twin?


Artist's image of our sun, along with his hypothetical solar companion.

Artist’s image of our sun, along with his hypothetical solar companion.
Image: M. Weiss

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

The hypothetical twin of our sun is long gone, but trace of it can be seen in the abundance of material located within the outer Oort Cloud, according to new research published in The Astrophysical Journal Letters.

The Oort cloud is the farthest region in the solar system, and lives a lot faruter then the outer planets and the Kuiper Belt. Unlike the Kuiper Belt, which is shaped like a donut, the Oort cloud is a massive and thick spherical shell that encloses the entire solar system. The inner Oort cloud starts at about 1,000 AU from the sun (where 1 AU is the average distance from Earth to the sun), while the outer edge stops at 100,000 AU.

This region of space is full of billions, possibly trillions, of rocky and icy objects left over from the formation of the solar system. According to the new paper, the abundance of material believed to exist in the outer Oort cloud is the result of our Sun’s early stint as a binary system.

Until now, computers trying to simulate the formation of the solar system, the part of objects located in the outer realm of the Oort cloud and the scattered disk – a specific population of trans-Neptunian objects outside the Kuiper Belt – do not reproduce. As a result, the origin of the outer Oort cloud is “an unsolved mystery”, according to the paper, written by astronomers Avi Loeb and Amir Siraj of the Center for Astrophysics at Harvard & Smithsonian.

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

“A stellar companion to the Sun would increase the chance of capturing objects from the Sun’s birth cluster,” Loeb wrote in an email. “The sun and its companion act as a fishing net that finds objects gravity when they pass by one of the two stars and lose energy by kicking it a little.”

By birth cluster, Loeb refers to a cluster of stars that formed together in the same molecular cloud, also known as a stellar infant shelter.. Starclusters eventually spread, though of strong staring winds as tidal forces exerted by the Milky Way system itself. De Sun’s hypothesis twin would be far, far drawn away.

‘The popular theory associates the origin of the Oort cloud with pun left over from the formation of’ esolar system, ”said Loeb. ‘Objects were scattered across the planets to great distances. But this model has difficulty reproducing the observed relationship between the scattered disk population of objects and the more spherical Oort cloud. Our model can account for the ratio. ”

The second sun hypothesis, to capture this redundant material, would require a mass similar to our own Sun. In, basically a twin. The two stars would be roughly 1,000 AU apart, according to the new model.

“It is entirely 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 solar-like stars are born as multiples, which later dissociate. ”

Rough how many heavenly material would have been lost when the two stars separated, but the authors claim that enough material remained to explain the Oort cloud. Continuing stars in the birth cluster were probably responsible for separating the Sa fan his adopted companion, but not before our solar system conquered its outer population of objects, namely the Oort cloud and – perhaps – the escaping Planet Nine. This gigantic hypothetical planet, describeed by Batygin and his Caltech colleague Mike Brown in 2016, is thought to exist in the outer solar system due to the peculiar clustering of certain Kuiper Belt otopics.

A story about the departure of origin for Planet Nine is that it formed as a gas giant in the inner solar system, but that it went into the outer solar system, after running too close to Jupiter. The new paper offers an alternative scenario: Planet Nine was captured by our solar system.

“The formation puzzle is not only about the Oort clouds, but also the extreme trans-Neptunian objects, such as the potential Planet Nine,” Loeb said. ‘It’s unclear where they came from, and our model predicts that there should be more objects with a similar orbital orientation than Planet Nine. ”

Indeed, Planet Nine could be a literal ninth planet as a whole population of dwarf planets, or even a massive ring of pun.

“Siraj and Loeb lay out a new idea for the early history of our solar system and give an interesting new survey on 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 study, said in an email. “It is noteworthy that the authors present a testable hypothesis in the form of an abundance of dwarf planets, and it will be very 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. Finding the long-lost twin of our Sun could be intrusively tricky. As Siraj remarked in a Harvard & Smithsonian press release, this lost star “could now be anywhere in the Milky Way.”

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

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