From a Different Star: 3I/ATLAS in the context of the Ōtautahi-Oxford interstellar object population model
arXiv:2507.05318 · doi:10.3847/2041-8213/adfbf4
Abstract
The discovery of the third interstellar object (ISO), 3I/ATLAS (`3I'), provides a rare chance to directly observe a small body from another Solar System. Studying its chemistry and dynamics will add to our understanding of how the processes of planetesimal formation and evolution happen across the Milky Way's disk, and how such objects respond to the Milky Way's potential. In this Letter, we present a first assessment of 3I in the context of the Ōtautahi-Oxford model, which uses data from Gaia in conjunction with models of protoplanetary disk chemistry and Galactic dynamics to predict the properties of the ISO population. The model shows that both the velocity and radiant of 3I are within the expected range. Its velocity predicts an age of over 7.6 Gyr and a high water mass fraction, which may become observable shortly. We also conclude that it is very unlikely that 3I shares an origin with either of the previous two interstellar object detections.
Accepted for publication in ApJL
References in corpus (14)
- Origin and evolution of moving groups I. Characterization in the observational kinematic-age-metallicity space
- The Natural History of 'Oumuamua
- The carbon monoxide-rich interstellar comet 2I/Borisov
- Evidence that 1I/2017 U1 (`Oumuamua) was composed of molecular hydrogen ice
- The Nucleus of Interstellar Comet 2I/Borisov
- `Oumuamua as a messenger from the Local Association
- Constraints on Radial Migration in Spiral Galaxies I. Analytic Criterion for Capture at Corotation
- Prospects for Backtracing 1I/`Oumuamua and Future Interstellar Objects
- Oort cloud Ecology II: Extra-solar Oort clouds and the origin of asteroidal interlopers
- A hypothesis for the rapid formation of planets
- A search for the origin of the interstellar comet 2I/Borisov
- Evidence Suggesting that 'Oumuamua is the ~30 Myr-old product of a Molecular Cloud
- Predicting the water content of interstellar objects from galactic star formation histories
- Turning up the heat on `Oumuamua