The rotation-activity connection for low mass stars

Recently a large number of rotation period measurements of low mass stars oftype M have become available. Surprisingly, one finds that in addition to thewellknown rapid rotators a population of very slowly rotating M dwarfs withrotation periods exceeding 100 days. These slow rotators pose a challenge forthe usual rotation activity paradigm, since about a third of these stars havebeen detected in the ROSAT allsky survey, even though the RASS data did notprobe significantly deeper than the saturation limit for stars of masses below0.6 MSun. We thus propose XMM followup for a complete sample of nearby,undetected low mass stars with long rotation periods down to a sensitivity limitof L_X/L_bol virgul 2 10**5 to study the relation between Xray activity and rotation in these stars. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]