Research Division Seminar
Testing different spectroscopic techniques for the characterization of solar-like stars

Abstract

The ESA's PLATO mission is mainly aimed at finding exoplanets similar to Earth, orbiting around sun-like stars. The characterization of the planets strongly depends on that of their host stars. A precise determination of some fundamental stellar parameters can be achieved from spectroscopic observations. High-resolution optical echelle spectra from HARPS and PEPSI were used to resemble observations at lower resolving powers R= 5000, 11 200, 20 000, and 65 000, for high and low signal to noise ratios, in order to establish the necessary strategy to properly characterize a sample of stars. The effective temperature, metallicity, microturbulence, and surface gravity were derived from different techniques based on either spectral synthesis or equivalent widths. This was performed by independent research teams belonging to the PLATO consortium. For the exercise, the teams worked on the same dataset without knowing the identity of the stars. The results obtained are compared to judge which techniques are the best in terms of accuracy for every resolving power. This talk summarizes the results of this blind competition.