10
Complicated
T dependence at the very edge
•We see emission lines at some
wavelengths:
–Implies very THIN HOT overlying gas at
top of atmosphere
–Gas is so thin it has trouble radiating
heat away
–Sound waves or magnetic fields heat
thin gas
•Chromosphere (“colored region” glows at a few wavelengths)
•Corona (“crown” seen during solar eclipses)
•Solar Wind ( escaping wind of tenuous gas)
From our text: Horizons, by Seeds