1st known interstellar visitor gets weirder: Oumuamua had probably 2 stars

An artistic illustration of the asteroid ‘Oumuamua, the first interstellar object ever known to visit our solar system.

(M. Kornmesser/European Southern Observatory)

Our solar system is the first known interstellar visitor is probably even more alien than previously thought, a new study suggests.

The mysterious, needle-like object in the form of ‘Oumuamua, who was spotted in zoom by the Earth near in October last year, likely to arise in a two-star system, according to the study.

‘Oumuamua means “scout” in Hawaiian; the object was discovered by researchers from the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) at Haleakala Observatory on the island of Maui. [‘Oumuamua: The 1st Interstellar Visitor in Photos]

The astronomers could tell that the 1,300 feet long (400 meters) ‘Oumuamua was not here in the area, on the basis of the hyperbolic orbit, which showed that the object was not gravitationally bound to the sun. At first, scientists thought that the body was probably a comet. But Oumuamua displayed no cometary activity — no long tail, no cloud-like “coma” around its nucleus — even after getting relatively close to the sun, so it was soon classified as an asteroid.

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  • ‘Oumuamua means “scout” in Hawaiian

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  • NASA officials have said

  • Monthly Notices of the Royal Astronomical Society

“It is very strange that the first object is what we would see from outside our system would be an asteroid, because a comet would be a lot easier to notice, and the solar system raises many more comets than asteroids,” study lead author Alan Jackson, a postdoctoral researcher at the Centre for Planetary Sciences at the University of Toronto Scarborough, said in a statement.

But Oumuamua probably does not originate from a system such as ours, according to the new study. Jackson and his colleagues carried out computer modeling of the work, which will show that the systems with two close orbit around the star boat from asteroids is much more efficient than a-star-systems.

And there are a lot of these binary systems there are; previous research has shown that more than half of all Milky way stars have stellar companions.

No one knows for sure where ‘Oumuamua came from or how long ago this was by traveling through the deep space. But there is a big chance that it was born in a binary system that harbors at least one major, hot stars, according to the new study. That is because such systems are likely to be mainly rocky, in contrast to the icy bodies in orbit relatively close to each other, in the first ejection zone.

And ‘Oumuamua was probably started during his birth system’s planet-formation period, however long ago that may, Jackson and his team said.

‘Oumuamua its closest approach to the Earth — approximately 15 million miles (24 million kilometers) on Oct. 14. The object is now rolled in the direction of the outer solar system and is too distant and dim to study even with a large telescope since mid-December, NASA officials have said. But astronomers have gathered a wealth of information on Oumuamua while they can, and they will no doubt be mining this information for a long time to come.

“In the same way we use comets to better understand planet formation in our own solar system, perhaps it is this curious object can tell us more about how planets form in other systems,” Jackson said.

The new study was published today (March 19) in the journal Monthly Notices of the Royal Astronomical Society.

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