Evolution of cool spots on the surface of V410 Tau

Abstract

The activity of V410 Tau, a T Tauri star with periodic brightness variations, is studied. The evolution of spots on the star’s surface over 46 years is investigated by reconstructing inhomogeneities in the stellar surface temperature based on photometric measurements. Analysis of the distribution of filling factors f as functions of time and longitude on the star’s surface can be used to trace changes in the location of the dominant active area. In some cases, a second active area (longitude) separated by about 180° is detected. No reliable manifestations of switching of the positions of the active areas were detected. The position of the active area was stationary and the position of minimum brightness remained unchanged during a time interval of 4800 days (about 13 years), which ended by the end of 2002. Though the position of the brightness minimum remained virtually constant, the light-curve shape (asymmetry) and the spot “outline” in the reconstructed temperature maps exhibited variations. The star possesses considerable cool spots on its surface, whose fractional area is typically 32% and varies between 27% and 40%. Variations of the star’s brightness and spottedness on time scales of 4.8–5.5 years are most prominent.