NASA Herschel Science Center's Portal to the Cool Universe
Artist Concept • nhsc2013-007a • Wednesday, February 20th, 2013

One of the great curiosities in solar science is that our Sun’s outer atmosphere – the corona – is heated to millions of degrees when its visible surface is ‘only’ about 6000 degrees. Even stranger is a curious temperature minimum of 4000 degrees lying between the two layers, in the chromosphere. Now, using the Herschel space observatory, scientists have made the first discovery of an equivalent cool layer in the atmosphere of the Sun-like star, Alpha Centauri A.