Thermal bifurcation as a driver of stellar surface inhomogeneities It's Probably Not Too Important, But Read On!

Abstract

Cool gas in the heart of the hot solar chromosphere betrays itself through anomalously strong absorptions of 4.7 μm CO lines at the extreme limb, and off-limb emissions. The origin of the “cool clouds” is thought to be a thermal instability driven by the CO itself. Questions concerning the pervasiveness and detailed structure of the “thermally-bifurcated” zones are being addressed through stigmatic spectroscopy of the solar CO bands with the NSO McMath-Pierce telescope. Here, I report recent progress, and implications for surface thermal inhomogeneities on other stars.