Abstract
ABSTRACTSpectra of the He I λ10830 line have been obtained for 23 metal-poor stars, the majority of which are dwarfs ranging in metallicity from -2.1 ≤ [Fe/H] ≤ -0.8. The data were acquired with the NIRSPEC spectrograph on the Keck II telescope. Most of these subdwarfs and dwarfs are found to exhibit a He I absorption line indicative of the presence of chromospheres. The equivalent width of the λ10830 absorption profile is generally less than 70 mÅ, and covers a range similar to that found in solar metallicity stars of low activity. Among the subdwarfs the λ10830 equivalent width does not correlate with either [Fe/H] metallicity or (B - V) color. Some evidence for asymmetric profiles is found among metal-poor dwarfs, but not the high-speed blue-shifted absorption displayed by some metal-poor red giants.
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