Correlation between activity indicators: Hα and Ca II in M stars

BUCCINO, A P; IBAÑEZ BUSTOS, R.V.; MAUAS, P J D

Congreso; 61a Reunion Anual de la Asociación Argentina de Astronomía; 2019

The magnetic fields responsible for the stellar activity are generated by the stellar dynamo mechanism. Several late-type stars present activity cycles similar to the 11-year solar. The standard stellar activity indicator used is the Mount Wilson S-index. However, due to the low intrinsic luminosity of dM stars the S index is notalways suitable for studying the chromospheric activity on these fainter stars. Therefore, it is necessary to theexplore redder activity indicators in late-type stars. It is well known that the correlation between the the Ca IIand Hα line-core fluxes is positive in the solar case for the whole solar-cycle.In this work, we present a particular study of the relation between Hα and Ca II in a set of 14 M starsfrom the observations obtained under the HKα Project, which operates in the Complejo Astron´omico ElLeoncito (CASLEO) since 1999.