On the association of solar radio emission and solar prominences.
Abstract
We have examined prominence cinematograms made at Sacramento Peak and Climax in the years 1949-1955 and compared them with the solar radio records at 167 Mc/s. No close connection was found between limb events and radio events, but some eruptions were found to be associated with simultaneous radio bursts. Three such cases are discussed in detail. These appear to produce a series of storm bursts of spectral type I. The radio emission appears to originate from points in the corona at the leading edge of the disturbance. The limb passages of large sunspot groups in 1949-1955 were studied on both cinematograms and single exposure surveys with the view of finding a criterion for radio-active spots. It was found that spot groups showing looped prominences and downward streaming from the corona showed a marked tendency to produce radio storms. Of 14 spots producing enhanced radio levels, 12 showed this criterion; 9 out of 10 large spots (>800 X 10-6 of the disk) with loops and streamers produced enhanced radio emission. This result is ascribed to the fact that the seat of such storms must lie in the corona and in the presence of strong ordered magnetic fields; the existence of such conditions is indicated by the presence of looped prominences. This work was supported by the Air Force Cambridge Research Center, Geophysics Research Directorate, through contract AF 19(604)- 969 with the High Altitude Observatory. Cosnmonwealth ScThntzfic and Industrial Research Organization, Sydney, Australia, and High Altitude Observatory, University of Colorado, Boulder, Colo.
- Publication:
-
The Astronomical Journal
- Pub Date:
- 1956
- DOI:
- 10.1086/107398
- Bibcode:
- 1956AJ.....61Q.193W