Stars identified as potential places of origin for interstellar asteroid
The object known as ‘Ouamuamua may have reached the solar system after a journey from one of four stars lasting millions of years.
Four stars have been identified as possible birth places of an interstellar asteroid that invaded our solar system last year.
The 800ft long dark-red cigar shaped object, given the Hawaiian name ‘Oumuamua, was so mysterious that there were serious suggestions it could be artificial.
In the end observations proved that it was a highly unusual comet-like asteroid and not an alien artefact.
Astronomers used the European Space Agency’s Gaia orbiting telescope to trace back ‘Oumuamua’s trajectory.
From a starting total of seven million stars, the scientists identified four dwarf stars that would have been in the right place to have “launched” ‘Oumuamua between one and seven million years ago.
Scientists believe the object was cast out from home and reached our solar system after an epic journey through space.
There is a problem, however.
None of the identified stars is known either to harbour planets or be part of a binary star system.
A giant planet or companion star would have been the most likely cause of the object’s ejection.
Gaia project scientist Dr Timo Prusti said: “While it’s still early to pinpoint ‘Oumuamua’s home star, the result illustrates the power of Gaia to delve into the history of our Milky Way galaxy.”
The research has been accepted for publication in Astronomical Journal.
