SOHO reads hottest temperatures yet in corona

17 Jun 2002

100-million K temperatures in the sun's corona have been detected by the Solar and Heliospheric Observatory (SOHO) satellite. Measurements at ultraviolet wavelengths show that oxygen ions at one point above the sun's north pole simmered at a temperature far higher than had been seen before in the corona; at a distance of 0.9 solar radii, the oxygen-ion temperature was 100 million K. These results, reported a few weeks ago at the American Astronomical Society add to the mystery of why the corona should be so much hotter than the solar surface.