FRASCA, AntonioAntonioFRASCAMontes, D.D.MontesALCALA', JUAN MANUELJUAN MANUELALCALA'Klutsch, A.A.KlutschGuillout, P.P.Guillout2020-10-142020-10-1420180001-5237http://hdl.handle.net/20.500.12386/27790In this paper we present the results of a simultaneous BVRI and Hα photometric monitoring, contemporaneous to medium-resolution spectroscopy of six T Tau stars in the Taurus-Auriga star forming region. We have characterized the Hα photometric system using synthetic templates and the contemporaneous spectra of the targets. We show that we can achieve a precision corresponding to 2-3 Å in the Hα equivalent width, in typical observing conditions. <P />The spectral analysis has allowed us to determine the basic stellar parameters and the values of quantities related to the accretion. In particular, we have measured a significant veiling only for the three targets with the strongest Hα emission (T Tau, FM Tau, and DG Tau). <P />The broad-band photometric variations are found to be in the range of 0.05-0.70 mag and are often paired to variations in the Hα intensity, which becomes stronger when the stellar continuum is weaker. In addition, we have mostly observed a redder V-I and a bluer B-V color as the stars become fainter. For most of the targets, the timescales of these variations seem to be longer than the rotation period. One exception is T Tau, for which the broad-band photometry varies with the rotation period. The most plausible interpretation of these photometric and Hα variations is that they are due to non-stationary mass accretion onto the stars, but rotational modulation can play a major role in some cases.STAMPAenArticle10.32023/0001-5237/68.4.52-s2.0-85060044763000464124600005http://acta.astrouw.edu.pl/Vol68/n4/a_68_4_5.html2018AcA....68..403FFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering