Convection in the envelopes of red giants

Abstract

The nature of convection in the envelopes of red giants is investigated, and the linear convective modes are computed to demonstrate the consistency of the mixing length theory. The mixing length at a given depth is tentatively identified with an equivalent width of the luminosity profile of the convective eigenmodes. The dominant convective element turns out to be comparable in size to the radius of the star, and this could account for the observed irregular variations in red giants.