- Press Release
- September 23, 2022
The Interstellar Interlopers
Interstellar interlopers are bodies formed outside of the solar system but observed passing through it. The first two identified interlopers, 1I/`Oumuamua and 2I/Borisov, exhibited unexpectedly different physical properties.
1I/`Oumuamua appeared unresolved and asteroid-like whereas 2I/Borisov was a more comet-like source of both gas and dust. Both objects moved under the action of non-gravitational acceleration. These interlopers and their divergent properties provide our only window so far onto an enormous and previously unknown galactic population. The number density of such objects is ∼ 0.1 AU−3 which, if uniform across the galactic disk, would imply 1025 to 1026 similar objects in the Milky Way.
The interlopers likely formed in, and were ejected from, the protoplanetary disks of young stars. However, we currently possess too little data to firmly reject other explanations.
David Jewitt, Darryl Z. Seligman
Comments: 40 pages, 19 figures, 7 tables, invited review in ARA&A Volume 61, submitted, comments welcome
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA)
Cite as: arXiv:2209.08182 [astro-ph.EP] (or arXiv:2209.08182v1 [astro-ph.EP] for this version)
From: Darryl Seligman
[v1] Fri, 16 Sep 2022 22:08:36 UTC (2,665 KB)