The lost siblings of the sun

Abstract

The anomalous chemical abundances and the structure of the Edgeworth-Kuiper belt observed in the solar system constrain the initial mass and radius of the star cluster in which the Sun was born to M ≃ 500-3000M and R ≃ 1-3 pc. When the cluster dissolved, the siblings of the Sun dispersed through the galaxy, but they remained on a similar orbit around the Galactic center. Today these stars hide among the field stars, but 10-60 of them are still present within a distance of 100 pc. These siblings of the Sun can be identified by accurate measurements of their chemical abundances, positions, and their velocities. Finding even a few will strongly constrain the parameters of the parental star cluster and the location in the Galaxy where we were born. © 2009. The American Astronomical Society. All rights reserved.