Astronomers Identify Four Star Systems That May Have Been Oumuamua's Original Home

Wednesday, 26 September 2018 - 12:12PM
Astronomy
Space
Wednesday, 26 September 2018 - 12:12PM
Astronomers Identify Four Star Systems That May Have Been Oumuamua's Original Home
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image credit: European Southern Observatory/M. Kornmesser CC BY 2.0
We've made a lot of discoveries about Oumuamua since it streaked into our solar system last November, but the mystery of its origins persists. At least one study claimed that it came from a binary star system whose extreme gravity shot it into interstellar space like a bullet, but most theories that aim to explain where Oumuamua comes from depend on knowing what it's made of: is it a rocky asteroid, an icy comet, or a combination of both?  Well, based on a new study led by astronomer Coryn Bailer-Jones of the Max Planck Institute for Astronomy, we now have some potential answers to the questions of where Oumuamua came from and what exactly it is: Oumuamua is most similar to a comet, and it most likely came from one of four star systems.

The conclusions are based in part on another piece of research published by astronomer Marco Micheli, who claimed that Oumuamua's orbit within our solar system couldn't be explained by a normal 'free fall,' ie being pulled by gravity. Instead, Oumuamua's velocity seemed to have something extra that was pushing it to accelerate, which Micheli's research identified as melting ice producing a comet-like stream of gas that acted like a 'weak rocket engine'.

Based on that information, Bailer-Jones' team began delving into the massive data dump provided by the ESA's Gaia satellite, which gave astronomers insight into the position, movements, and distances of billions of stars. After modeling the movements of a huge patch of stars (about 7 million of them) and charting the trajectory of Oumuamua, they found four potential star systems that may have been its original home: a dwarf star named HIP 3757, a star called HD 292249, and two other stars that astronomers don't have much data on.

These findings are still tentative, but at least we have some idea where Oumuamua came from. The real question is where it's going now; what strange new worlds will it—oh, it's headed for the Pegasus constellation.



Cover image credit: European Southern Observatory/M. Kornmesser  CC BY 2.0
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