Saturn radio emission near 1 MHz.
Abstract
Radio emissions from the direction of Saturn are analyzed which were observed by IMP-6 at 15 frequencies between 375 and 2200 kHz from April 1971 to October 1972. The radio bursts are identified in the IMP-6 data by a phase analysis of the spin-modulated signal from the spacecraft's dipole antenna, and approximately 12 storms are isolated whose occurrence corresponded to times when the spacecraft had an unobstructed view in the direction of Saturn. The spectral character of the radiation is found to be analogous to that of Jupiter, and a power-spectral analysis of the storm occurrence times indicates a weak periodicity for some of the observing frequencies. The Saturnian emission most similar to Jupiter's decametric emission is found to be strongest at 1100 kHz with a bandwidth of about 1000 kHz. A secondary spectral peak may exist at 400 kHz, which is similar to that observed for Earth and Jupiter. The detection of this nonthermal radio emission is shown to be the first direct evidence for the existence of a Saturnian magnetic field containing energetic particles.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1975
- DOI:
- 10.1086/181819
- Bibcode:
- 1975ApJ...198L..89B
- Keywords:
-
- Planetary Magnetic Fields;
- Planetary Radiation;
- Power Spectra;
- Radio Emission;
- Saturn (Planet);
- Emission Spectra;
- High Frequencies;
- Nonthermal Radiation;
- Particle Energy;
- Radio Bursts;
- Time Response;
- Lunar and Planetary Exploration