The CARMENES search for exoplanets around M dwarfs. The He I triplet at 10830 $\mathring{\mathrm{A}}$ across the M dwarf sequence

B. Fuhrmeister, S. Czesla, L. Hildebrandt +24

The He I infrared (IR) triplet at 10830 AA is an important activity indicator for the Sun and in solar-type stars, however, it has rarely been studied in relation to M dwarfs to da…