An H-alpha survey of southern hemisphere active chromosphere stars

Because of the variety of extraordinary phenomena exhibited by active chromosphere objects, discovery of new, bright surface-active stars is of considerable importance. Ca II emission is a well-known signature of chromospheric activity, serving even as one of the points of definition of the class of RS CVn binary stars. In connection with the present investigation, spectroscopic observations of 27 Ca II emission stars have been conducted. The observations make it possible to identify unambiguously the most chromospherically active stars in the sample. By observing the H-alpha line, rather than H and K, it is possible to distinguish nine of these stars which are likely to be observational targets as interesting as the extremely surface active objects V711 Tau or FK Com. Of the 27 stars surveyed, two (HD 86005, HD 204128) showed H-alpha as an emission feature above continuum, with estimated equivalent width 1-2 A.