Benchmark stars

data-driven spectroscopy depends on the accuracy of the reference used

Constraining the models of formation and evolution of the Galaxy requires to know the positions, velocities, ages and chemical compositions of as many stars as possible. Thanks to modern surveys, in particular those resulting from ground-based multi-spectrographs, atmospheric parameters and chemical abundances are known for millions of stars. To efficiently and accurately characterise these large amount of stars,  we need reference objects to calibrate and validate the methods. 

We provide the community with different sets of benchmark stars and perform detailed analysis of their spectra. The Gaia FGK benchmark stars, in particular,  benefit from interferometry for which a radius is known independently from spectra. They constitute the calibration pillars of surveys like Gaia ESO, GALAH and RAVE. With my close colleagues Caroline Soubiran from Bordeaux and Ulrike Heiter from Uppsala, we lead the assembly of such stars and characterise their spectra. That requires to understand the state-of-the-art in the field of industrial spectroscopy, which we managed to summarise in our latest Annual Review for Astronomy and Astrophysics:

Accuracy and presicion of industrial stellar abundances, 2019, ARA&A

In addition to keep improving our sample, with this work I have been able to bring expertise to the Sloan Digital Sky Survey collaboration as lead of the "Abundances Working Group" and to the ESA PLATO collaboration, as member of the "Benchmark Stars Working Group" lead by Orlagh Creevey from Nice.