A Uniform Statistical Analysis of Jovian Decameter Radiation, 1950

Abstract

1960. JAMES N. DOUGLAS, Yale University -A permanent I B M -card catalogue has been initiated of all of the known Jupiter decameter radio noise storms, kindly made available by C. Shain, B. Burke, K. Franklin, R. Gallet, J. Kraus, G. Reber, A. Smith, and T. Carr, and supplemented with four years of multichannel observations at Yale. Uniform statistical analysis of this material establishes the radio (presumably also the solid-body) rotation period of Jupiter as 9h55rn298.37 *0S.16 s.d. A provisional definition of "radio longitude" follows as =Mi$0.2742 (t-2433339.5000), with )y the radio longitude, X23 the familiar System II longitude, and tin Julian days. Within the precision of the existing data, the period has been constant over the ten years of observation from 1950 to 1960, over the frequency range from 18 to 27 Mc, and for the three principal regions of emission whose radio longitudes are 760*13, 1780*7 and 2540*15. The width of the major, 1780, peak declines with frequency as noted by other observers, being 600 at 18 Mc, 470 at 20 Mc and 400 at 22.2 Mc. It is interesting to note that the two minor peaks are separated by 1800 in longitude. While the three peaks are usually well defined, there is evidence that they may not be completely independent. The shape of the occurrencefrequency histogram correlates significantly with the solar elongation of earth as seen from Jupiter. Also in the combined data there appears to be a significant correlation with solar activity, delayed three or four days, in general agreement with Warwick's findings. This work was made possible by Research Corporation, NSF, and NASA grants.