  The X-ray flares of NGC 5905, RX J1242.6-1119A, and RX J1624.9+7554 observed
by Chandra in 2001 and 2002 have been suggested as the candidate tidal
disruption events. The distinct features observed from these events may be used
to determine the type of a star tidally disrupted by a massive black hole. We
investigate these three events, focusing on the differences for the tidal
disruption of a giant star and a main sequence, resulted from their different
relation between the mass and the radius. We argue that their X-ray flare
properties could be modeled by the partial stripping of the outer layers of a
solar type star. The tidal disruption of a giant star is excluded completely.
This result may be useful for understanding the growth of a supermassive black
hole by capturing stars, versus the growth mode through continuous mass
accretion.
