Continuando com a discussão das anãs vermelhas, Travis Metcalfe diz-me que realmente as anãs vermelhas se transformam em gigantes vermelhas e explica o processo. Se ele tem razão ou não é coisa que ainda não sei?
A red giant expands when hydrogen is burning in a shell around the degenerate helium core. As this core contracts under the influence of gravity it releases extra heat that causes the hydrogen shell to burn faster -- releasing the extra energy that puffs up the outer layers. So it should work the same way in a red dwarf. Shedding the outer layers entirely requires a stellar wind -- and we don't really know what causes these winds in more massive stars, so it's unclear how that process would translate for red dwarfs. There is no direct observational evidence of the process because the main sequence lifetime of a red dwarf is longer than the present age of the universe. So helium core white dwarfs are currently only formed in binary systems, where it is easy to strip off the outer layers.
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