The solar siblings in the Gaia era

TL;DR

This study simulates the Sun's birth cluster to estimate the current number of solar siblings detectable by Gaia, emphasizing the need for combined chemical and kinematic methods for identification.

Contribution

It provides the first realistic predictions of solar sibling distribution in Gaia data and highlights the challenges of identification using phase space alone.

Findings

Approximately 100 solar siblings detectable by Gaia in the best case

Phase space search alone is highly challenging for identifying siblings

Combining chemical tagging with kinematic data is essential for success

Abstract

We perform realistic simulations of the Sun's birth cluster in order to predict the current distribution of solar siblings in the Galaxy. We study the possibility of finding the solar siblings in the Gaia catalogue by using only positional and kinematic information. We find that the number of solar siblings predicted to be observed by Gaia will be around 100 in the most optimistic case, and that a phase space only search in the Gaia catalogue will be extremely difficult. It is therefore mandatory to combine the chemical tagging technique with phase space selection criteria in order to have any hope of finding the solar siblings.