Accession Number : AD0657186

Title :   THE SOLAR X-RAY FLARE OF 7 JULY 1966,

Corporate Author : IOWA UNIV IOWA CITY DEPT OF PHYSICS AND ASTRONOMY

Personal Author(s) : Van Allen,J. A.

Report Date : JUL 1967

Pagination or Media Count : 36

Abstract : By means of a mica window Geiger-Mueller tube on earth satellite Explorer 33, a major solar x-ray flare was observed with 81.8 sec time resolution on 7 July 1966. The flare had its onset at 00:23, its maximum intensity at 00:42, and a total duration of 200 minutes. The maximum energy flux was 0.03 ergs/sq cm sec and the time integrated flux was 97 ergs/sq cm (2 < lambda < 12 deg. A). Assuming equal intensity over 2 pi-steradians at the sun, the total emission in this wave length band was 1.4 x 10 to the 29th power ergs and the maximum surface luminosity of the sun was 2.9 x 10 to the 6th power ergs/sq cm sec or 4.5 x 10 to the -5 power of the whole radiant luminosity of the average solar surface. Charged particles began to arrive at the satellite at 00:58, or 35 minutes after the first detection of the x-ray enhancement, and remained in the interplanetary system for at least ten days thereafter. The intensity-time curve of the soft x-rays is compared with those of 2700 MHz solar radio noise flux and of ionospheric absorption at 22 MHz as observed at Pentiction. (Author)

Descriptors :   (*SOLAR FLARES, X RAYS), SCIENTIFIC SATELLITES, GEIGER COUNTERS, COSMIC RAYS, SPACE ENVIRONMENTS, SOLAR DISTURBANCES, RADIATION MEASURING INSTRUMENTS

Subject Categories : Astrophysics
      Nuclear Instrumentation

Distribution Statement : APPROVED FOR PUBLIC RELEASE