The Lyot Ha-heliograph at the Royal Observatory, Cape of Good Hope was in almost daily operation from March 12, 1958 to l)ccember 31, 1965. I-rom the records obtained, a delinitix,e list of 2907 flares was compiled, their properties analyzed, and the results presented herein.The data on East-West distribution o[" activity, although inconclusive, shows an asymmctry ot" flare activity with 56.5 ~o of the flares West of the central meridian ; this is partially due, however, to an inhon~ogcncous density distribution in the filtcrgrams.Flare distribution with respect to hcliographic longitude, association ~x.ith spot types and number of spots in the group arc also discussed. The frequency of flare areas, rise times, ,'rod durations arc examined as is their relationship to distance from the disk centre.
A SOLAR flare in the 3+ category of importance and of exceptionally large extension was observed on June 1 at the Royal Greenwich Observatory, Herstmonceux, and at a number of other solar stations in Europe. We have recently been analysing the film in Hr:x light taken with the Lyot heliograph . at the Royal Observatory, Cape of Good Hope, which gives a complete record of the flare at 1-min. intervals under cloudless conditions.The spot group over which the flare occurred was of complex E-type containing 24 spots and had extended rapidly in area since its first appearance on the east limb on May 29. The flare began at 0823 u.T. and developed rather slowly until about
In recent years, considerable attention has been given to the conjugate aspects of various phenomena at auroral latitudes resulting from electron precipitation on the atmosphere. By and large, most of these observations have been in connection with bay‐type magnetic disturbances. Only recently [Nagata et al., 1963; Chivers and Hargreaves, 1965] has consideration been extended to other, less frequent, disturbances such as slow pulsations having periods of the order of several hundred seconds.
With the aim of adding to the information about conjugate aspects of these rarer events, the present letter summarizes observations of a long‐period pulsation event in ionospheric absorption of cosmic radio noise at Kotzebue, Alaska (66.87°N latitude, 162.50°W longitude), and the Australian National Antarctic Research Expeditions' station at Macquarie Island (54.50°S latitude, 158.95°E longitude). Though this record shows a striking degree of simultaneity and similarity, additional features of pulsating electron precipitation are brought forward from X‐ray and riometer observations outside the immediate vicinity of the conjugate regions, indicating spatial structure on a scale of a few hundred kilometers.
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