The PolarBase archive of stellar spectra

PolarBase is an online archive offering stellar data collected with the ESPaDOnS and NARVAL high-resolution spectropolarimeters, in their reduced form. All spectra feature a continuous coverage of the 370-1,000 nm spectral domain, at a spectral resolution of 65,000. As of 2022, observations of 4,700+ stellar objects throughout the Hertzsprung-Russell diagram are available for a total of more than 2x105 spectra. Intensity spectra are offered for all targets, and the majority of the observations also include simultaneous spectra in circular or linear polarization. Most observations are associated with a cross-correlation profile, significantly increasing the detectability of weak polarized signatures. Stokes V Zeeman signatures are detected for about 500 stars of all masses and evolutionary stages, and linear polarization is detected in a few dozen targets. This unique set of Zeeman detections offers the first opportunity to run homogeneous magnetometry studies throughout the H-R diagram. The web interface of PolarBase is available at http://polarbase.irap.omp.eu.