The mystery & # 39; Oumuamua & # 39; may not be so mysterious after all

Oumuamua, as shown by the William Herschel telescope.
Image: NASA; Alan Fitzsimmons (RCAF, Queen's University Belfast), Isaac Newton Group (Wikimedia Commons)

According to a new study, the first interstellar object to have visited the solar system "defied expectations" in 2017 and raised many questions, especially whether it was a comet or a comet. an asteroid (or, as some would like to believe, a stranger). spatialship). Although some studies have determined that it was an asteroid, new research concludes that the comet hypothesis could still be plausible.

"Oumuamua first appeared on October 19, 2017 in the Hawaiian telescope data Pan-STARRS. Rather than orbiting the Sun, his trajectory clearly implied that he had come from outside the solar system and then left. Although he did not stay long, the scientists were able to make 818 observations of the object and found some strange things. It had an elongated shape with a complex rotation. And strangely, it accelerated by accelerating – more than would be caused solely by the effects of the gravity of the Sun.

The debate raged as to whether the rock is a comet, an icy body coming from the outer regions of a star system with a kind of fuzzy atmosphere and a tail; an asteroid, a tailless rock that has formed closer to its star; or something else entirely. Although the release of gas from the surface (as of a comet) could have explained the abnormal acceleration, 'Oumuamua has no observable tail nor observable carbon gas spouting from its surface. Scientists then wondered if this might be something else, perhaps even a flat object like a solar sail that accelerates with the thrust of the Sun's particles.

But a new paper by Yale, Darryl Seligman and Greg Laughlin, as well as Caltech's Konstantin Batygin, which is expected to be published in The Astrophysical Journal, is putting the brakes on speculation. He repeats that a "volatile degassing structure rich in volatile substances for" Oumuamua provides the simplest explanation of its strange trajectory ". In other words, even though we have neither seen the gas nor the tail, it looks more like a comet.

This document simulated an elongated pill-like object that emits a vapor-like jet of vapor-like particles, mainly water vapor, which could explain why we did not see a tail. The model produced results that closely resembled those observed in 'Oumuamua, including tipping behavior and additional acceleration.

Unsurprisingly, early opponents of the comet hypothesis are not convinced by the new findings (are people ever convinced by opposing arguments?), Reports Lee Billings of Scientific American. Harvard's Avi Loeb said the new discoveries are based on the assumption that extrasolar objects act like objects in the solar system, while Roman Rafikov of Cambridge University said the paper called for the comet to be an ideal form. .

So, little has changed and astronomers still do not agree on the nature of Oumuamua. Hope that other interstellar objects will soon visit the solar system, which will provide us with more information to study and debate.

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