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Centro de Astrofísica da Universidade do Porto

Is LkHα 264 like a young, extremely active Sun?

V.M. Costa, J. F. Gameiro, M. T. V. T. Lago

Abstract
We combine calibrated International Ultraviolet Explorer (IUE) archive data and new low-resolution optical data for the T Tauri star LkHα 264 covering the region from 1200 to 7000┼. The UV continuum is well fitted by the combination of a blackbody at 4300K plus hydrogenic free-free and free-bound emission from a dense plasma at 3.5x104K plus the emission by a second blackbody. This last component is at T~8700K and covers about 4per cent of the stellar surface. We interpret this last component to be the result of emission from one or various hotspots. The interesting result is that this combined emission also fits the observed optical continuum well. We conclude that this star is an analogue of the Sun, however displaying a much higher level of activity.

Monthly Notices of the Royal Astronomical Society
Volume 307, Page L23
August 1999

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