id UPDATE: SPACE MYSTERY
In last issue’s Q& A we told you about the interstellar object named Oumuamua, which has mysterious origins in a far-off corner of space. Now scientists are reporting that they have found the vicinity of the cigar-shaped object, which has finally been classified as a comet despite the absence of a visible tail. Astrophysicist Jackie Faherty has said “Determining the home of Oumuamua is equatable to finding a needle in a haystack the size of Mount Everest,” and indeed the precise location still isn’t known. An international team of researchers using new data from the European Space Agency’s Gaia probe has narrowed it down to four dwarf stars that could be Oumuamua’s home. It is not known how it escaped its own system to reach us, though evidence suggests it was ejected by gravitational forces from a giant planet that orbits its home star. Oumuamua has been traveling for more than 1 million years and is the first known interstellar object to visit our solar system.
The Gaia space observatory’s purpose is to collect detailed data on more than 1 billion stars in the Milky Way. To leverage that data, the astronomers considered details for 7 million of the stars in Gaia’s repository, along with another 220,000 that have already been cataloged. After a great deal of calculation, they’ve identified four stars that came within a few light-years of Oumuamua between 1 and 7 million years ago. One is a reddish dwarf called HIP 3757, another is a sunlike star called HD 292249; not much is known about the other candidates.
Perhaps someday more will be known about Oumuamua’s origins and researchers will be able to pinpoint which of the four stars it calls home. However it’s also possible Oumuamua hails from yet another star that is not currently visible to us.