Using heritability of stellar chemistry to reveal the history of the Milky Way

TL;DR

This paper applies biological phylogenetic methods to stellar chemistry data to uncover the evolutionary history of the Milky Way, revealing population transitions and star formation events.

Contribution

It introduces a novel interdisciplinary approach using phylogenetics to analyze stellar populations and reconstruct the Galaxy's evolutionary history.

Findings

Thick disk is ancestral to the thin disk

Detected a star formation burst during disk transition

Identified signatures of Solar System formation variability

Abstract

Since chemical abundances are inherited between generations of stars, we use them to trace the evolutionary history of our Galaxy. We present a robust methodology for creating a phylogenetic tree, a biological tool used for centuries to study heritability. Combining our phylogeny with information on stellar ages and dynamical properties, we reconstruct the shared history of 78 stars in the Solar Neighbourhood. The branching pattern in our tree supports a scenario in which the thick disk is an ancestral population of the thin disk. The transition from thick to thin disk shows an anomaly, which we attribute to a star formation burst. Our tree shows a further signature of the variability in stars similar to the Sun, perhaps linked to a minor star formation enhancement creating our Solar System. In this paper, we demonstrate the immense potential of a phylogenetic perspective and interdisciplinary collaboration, where with borrowed techniques from biology we can study key processes that have contributed to the evolution of the Milky Way.