We have obtained high-resolution echelle spectra of 18 solar-type stars that an earlier survey showed to have very high levels of Ca II H and K emission. Most of these stars belong to close binary systems, but 5 remain as probable single stars or well-separated binaries that are younger than the Pleiades on the basis of their lithium abundances and H-alpha emission. Three of these probable single stars also lie more than 1 magnitude above the main sequence in a color-magnitude diagram, and appear to have ages of 10 to 15 Myr. Two of them, HD 202917 and HD 222259, also appear to have a kinematical association with the pre-main sequence multiple system HD 98800.
@article{arxiv.astro-ph/9803111,
title = {High-Resolution Spectroscopy of Some Very Active Southern Stars},
author = {David R. Soderblom and Jeremy R. King and Todd J. Henry},
journal= {arXiv preprint arXiv:astro-ph/9803111},
year = {2009}
}