The escape velocity from the surface of the sun (618 km/s) corresponds to a temperature of about 50,000,000º Kpferkul wrote:So my question is: What force holds this very tenuous matter in place, since the gravity on the surface of Betelgeuse (6e-4 g's) is much lower than the gravity on the surface of our sun (28 g's)? Wouldn't the solar wind on Betelgeuse rapidly blow the "surface" away?
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Hence, only the hottest coronal gases are able to escape as solar wind.
While Betelgeuse's gravity is very weak it is a force that remains relatively constant over hundreds of millions of miles.
Hence, the escape velocity from the surface of Betelgeuse is still a quite respectable 87 km/s
corresponding to a temperature of about 1,000,000º K.
While Betelgeuse certainly cannot maintain a 1,000,000º K corona,
it's photosphere is still way too cold to evaporate as solar wind.