Rotational modulation of the wind of the PMS star AB AUR : new observations in C IV and MG II.

Abstract

In continuation of a time monitoring program devoted to short-term spectral variability in Herbig pre-main-sequence stars, new results are presented for the star AB Aur. On a one day time scale, the variability of the blue edge velocity of the Mg II 2795-A line is confirmed, and that of the C IV 1548-A line established. Since the observations cover only 6 days, and since the phase coverage is not tight enough, the new data can only support the periodic variability of Vs found previously (Praderie et al, 1986; Catala et al., 1986). Periods between 40 and 50 h are possible. Scenarios for the wind model of AB Aur are discussed.