From a Different Star: 3I/ATLAS in the context of the Ōtautahi-Oxford interstellar object population model

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

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Cited by in corpus (7)

• Very Large Telescope Observations of Interstellar Comet 3I/ATLAS. II. From Quiescence to Glow: Dramatic Rise of Ni i Emission and Incipient CN Outgassing at Large Heliocentric Distances*
• Interstellar Comet 3I/ATLAS: Evidence for Galactic Cosmic Ray Processing
• The Volatile Inventory of 3I/ATLAS as seen with JWST/MIRI
• Near-Discovery SOAR Photometry of the Third Interstellar Object: 3I/ATLAS
• Dynamical simulation of the Interstellar Comet 3I/ATLAS
• Pre-perihelion Volatile Evolution of Interstellar Comet 3I/ATLAS Indicating Significant Contribution from Extended Source in the Coma
• Icy Volatile Enhancements in Evolving Protoplanetary Disks