Oumuamua, the first confirmed interstellar asteroid known so far, probably originated from a dual star system or two stars orbiting a common center of gravity, a new study claims.
Researchers first spotted Oumuamua on October 19, 2017, using the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS), at Haleakala Observatory on the island of Maui. Initially, cigar-shaped Oumuamua was believed to be a comet. But as the 1,300-foot-long (400 meters) mysterious object did not display any cometary activity – no long tail and no cloud-like “coma” around its core – scientists reclassified the interstellar object as an asteroid.
The new study conducted by researchers from the University of Toronto suggests that Oumuamua probably didn’t come from a single star system. Using computer models scientists say that rocky objects like Oumuamua are far more likely to come from binary than single star systems. It is believed that systems with two close-orbiting stars ejecting asteroids much more efficiently than one-star systems.
The research team believes that Oumuamua probably came from a system with a relatively hot, high mass star since such a system would have a greater number of rocky objects closer in. As per the study, Oumuamua probably could have been ejected from its binary system in the initial years of planetary formation, which means that the asteroid has been flying through space for possibly millions of years at a speed of 30 km per second.
“It’s really odd that the first object we would see from outside our system would be an asteroid because a comet would be a lot easier to spot, and the solar system ejects many more comets than asteroids,” said Alan Jackson, from the University of Toronto in a statement, who is also the lead author of the study.
Jackson further pointed out Oumuamua’s orbit has the highest eccentricity ever observed in an object passing through our Solar System. He stressed that more research on Oumuamua is required to better understand how planet formation happens in the galaxy.
The study has been published in the journal Monthly Notices of the Royal Astronomical Society.