Stellar phylogenies 

Funded by Millenium Nucleus ERIS

We believe that a galaxy is composed by an evolving gas which forms stellar populations of different characteristics depending on the physical properties of the potential well at a certain location of this galaxy. We also postulate that FGK type stars of different ages and positions in the galaxy represent the fossil records of this evolving gas. 

We further acknowledge our limitation that only in the Milky Way can we resolve with enough accuracy these fossil records. In particular, the spectra taken by several ground based spectrographs provides us many chemical elements — stellar DNA — for many stars.

Phylogenetics is the reconstruction of evolutionary history by building trees that represent branching patterns and sequences. These trees represent shared history, and it is our contention that this approach can be employed in the analysis of the Milky Way history, where the shared environment in which stars form provide the basis for tree-building as a methodological tool.

We study how can we apply tree thinking in studying the evolution of the gas contained in our Galaxy using the chemical pattern of stars as DNA and applying well-tested genetic softwares to construct phylogenetic trees.  This is an exciting collaboration with my colleague and friend Payel Das from Surrey University, in addition to Robert Foley from Cambridge University, expert in evolutionary and biology studies.

Our latest paper was lead by Holly Jackson, an undergraduate student in computer science from MIT who came to visit me as part of the MISTI programme.

Much more is coming now through ERIS, the new Millenium Nucleus for the Evolutionary Reconstruction of the InterStellar medium: