Radio emission of the solar polar regions at millimeter wavelengths
Abstract
Observations of enhanced radio emission at millimeter wavelengths in the polar regions of the sun are reported. The solar poles were observed at 8.2 and 13.5 mm by a 22-m radio telescope in 1974, and at the same wavelengths plus 3.5 mm (using a 4-m telescope) in the fall of 1977. The angular size of the regions of enhanced radio brightness is found to be approximately the same (1.5-2 arcmin) at all wavelengths, however the contrast between the temperatures of the emission regions and the undisturbed sun is observed to have decreased since 1974. The decrease of contrast is accounted for by a decrease in the temperature of the polar regions following the solar cycle minimum.
- Publication:
-
Radio Physics of the Sun
- Pub Date:
- 1980
- DOI:
- Bibcode:
- 1980IAUS...86..141E
- Keywords:
-
- Millimeter Waves;
- Polar Regions;
- Solar Radio Emission;
- Brightness;
- Solar Temperature;
- Telescopes;
- Solar Physics