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Concept of the artist of the object "Oumuamua". He traveled in the space between the stars to reach our solar system. Image via ESO / M. Kornmesser.
At the end of 2017, astronomers became aware of an intruder in our solar system, a small object similar to an asteroid or a comet from another star system. Interstellar objects were expected, but this object – later called "Oumuamua" – was the first to be found. During the past year, studies have attempted to reconstruct the path of Oumuamua and thus learn its domestic solar system. But until now, they had not found any plausible candidates. This week (September 25, 2018), this has changed. A team of astronomers from the Max Planck Institute for Astronomy in Germany announced that she had followed Oumuamua on several hospitality systems. The team used data from ESA's Gaia satellite to find four plausible stars where "Oumuamua could have started his journey more than a million years ago.
Max Planck's Max Planck's Coryn Bailer-Jones led the team that was able to return to the Oumuamua movement and identify the four candidate stars. All four are dwarf stars, which is not surprising since dwarves are the most common star type in our Milky Way galaxy.
Various studies had already suggested that "Oumuamua was ejected from the planetary system of its star during the formation phase of the planet, while there were many small objects (planetesimals) that interacted with the giant planets of the system. .
Max Planck's team said that Oumuamua's original star would have two key properties. First, returning to Oumuamua's orbit should take us directly back to the original star or at least very close to it. Secondly, the relative velocity of "Oumuamua" and its original star will probably be relatively slow – objects are not usually ejected from their home systems at high speed. A statement from the institute said:
The closest to Oumuamua, about a million years ago, is the reddish dwarf star HIP 3757. It has approached about 1.96 light-years. Given the unexplained uncertainties in this reconstruction, it is close enough for Oumuamua to come from its planetary system (if the star has one). However, the relatively high relative speed (about 25 km / s [16 miles/s]) makes it less likely that it is the house of Oumuamua.
The next candidate, HD 292249, is similar to our sun, was a little less close to the trajectory of the object 3.8 million years ago, but with a relative speed of 10 km / s. [6 miles/s].
The two additional candidates met respectively "Oumuamua 1.1 and 6.3 million years at intermediate speeds and distances". These stars have already been cataloged by other surveys, but little is known about them.
These four stars remain plausible candidates, said these astronomers, but they also said:
… The smoking gun is still missing. To eject "Oumuamua at the observed speeds, the host system should have had a suitable giant planet that could launch Oumuamua into the depths of space.
Until now, no planet of this type has been detected around these stars, but as none of the stars has been closely examined for planets, this could well change in the past. ;to come up.
Learn more from the Max Planck Institute of Astronomy
This painting was not part of the study of "Oumuamua" by Bailer-Jones et al., But it gives you an idea of the path of this object in our solar system. Graph via Guy Ottewell's blog.
In summary: A team of astronomers from the Max Planck Institute of Astronomy has identified four plausible candidates for the host star of Oumuamua. "Oumuamua is the first object in interstellar space known to have crossed our solar system.
Source: Plausible origin stars of the interstellar object 'Oumuamua found in GaiaDR2
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