The lost siblings of the Sun

TL;DR

This paper discusses how the Sun's original star cluster's properties can be inferred from chemical and positional data of potential sibling stars still near the solar system, aiding understanding of our origins.

Contribution

It estimates the initial mass and size of the Sun's birth cluster and suggests methods to identify its sibling stars today.

Findings

Estimated Sun's birth cluster mass: 500-3000 solar masses

Predicted 10 to 60 sibling stars within 100 parsecs

Siblings can be identified through chemical and kinematic measurements

Abstract

The anomalous chemical abundances and the structure of the Edgewood-Kuiper belt observed in the solar system constrain the initial mass and radius of the star cluster in which the sun was born to $M\simeq500$ to 3000 \msun and $R\simeq 1$ to 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 to 60 of them are still present within a distance of $\sim 100$ 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.