Long Thin Loops Heated from their Base

Long Thin Loops Heated from their Base

. The low solar corona and transition region are filled with bright, thin magnetized loops that extend for hundreds of millions of meters above the visible solar disk, or photosphere, spanning 30 or more times the diameter of Earth. The coronal loops are filled with gas that is hundreds of times hotter than the photosphere. In this TRACE image, taken on 06 November 1999, the hot gas is detected in the ultraviolet light emitted by eight-and nine-times-ionized iron (Fe IX/X at 17.1nm) formed at a temperature of about 1.0 million degrees kelvin. Such detailed TRACE images indicate that most of the heating occurs low in the corona, near the bases of the loops as they emerge from and return to the solar disk, and that the heating does not occur uniformly along the entire loop length. (Courtesy of Markus J. Aschwanden, the TRACE consortium, LMSAL, and NASA.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University