• DOI:10.1126/science.1187535
• Corpus ID: 23671821

Capture of the Sun's Oort Cloud from Stars in Its Birth Cluster

@article{Levison2010CaptureOT,
  title={Capture of the Sun's Oort Cloud from Stars in Its Birth Cluster},
  author={Harold F. Levison and Martin J. Duncan and Ramon Brasser and David E. Kaufmann},
  journal={Science},
  year={2010},
  volume={329},
  pages={187 - 190}
}

• H. Levison, M. Duncan, +1 author D. Kaufmann
• Published 9 July 2010
• Physics, Geology
• Science

Out of the Oort Cloud Long-period comets originate from the Oort cloud, a vast reservoir of icy bodies that surrounds the solar system. These bodies are thought to be remnants from the formation of the solar system. But did they all form in the Sun's protoplanetary disk, or could they have been generated in the protoplanetary disks of other stars in the cluster where the Sun probably formed? Levison et al. (p. 187, published online 10 June) used detailed numerical simulations to investigate what fraction of comets might transfer from the outer reaches of one stellar system to another. The simulations suggest that a substantial number of comets can be captured through this mechanism, which may explain why the number of bodies in the Oort cloud is larger than models predict. Some Oort cloud comets may have originated in the protoplanetary disk of stars other than the Sun. Oort cloud comets are currently believed to have formed in the Sun's protoplanetary disk and to have been ejected to large heliocentric orbits by the giant planets. Detailed models of this process fail to reproduce all of the available observational constraints, however. In particular, the Oort cloud appears to be substantially more populous than the models predict. Here we present numerical simulations that show that the Sun captured comets from other stars while it was in its birth cluster. Our results imply that a substantial fraction of the Oort cloud comets, perhaps exceeding 90%, are from the protoplanetary disks of other stars.