The MG II Lines as Indicators of Solar and Stellar Activity

BUCCINO, A. P.; MAUAS, P. J. D.

Córdoba, Pcia de Córdoba, Argentina

Conferencia; X Reunion Regional Latinoamericana de Astronomia; 2002

Union Astronomica Internacional

We present profiles of the Mg II h and k lines, observed with IUE, for several solar type stars, including some which has been recently reported as having planetary systems. From the comparison with solar profiles we are able to infer the levels of stellar activity and variability, an important parameter for the search of extraterrestrial intelligence. Conversely, from these activity levels we can constrain the activity of the Sun in the past, which is important to assess the influence that changes in the solar emission could have had on the climatic change on earth.