Accession Number : AD0474416


Title :   OBSERVATIONS ON THE BEHAVIOR OF FILAMENTS DURING CHROMOSPHERIC FLARES,


Corporate Author : SACRAMENTO PEAK OBSERVATORY SUNSPOT NM


Personal Author(s) : Bruzek, Anton


Report Date : Jan 1951


Pagination or Media Count : 18


Abstract : From observational material obtained by a spectrohelioscope during 2-1/2 years, the behavior of filaments during the occurrence of chromospheric flares was investigated. Two principle cases can be distinguished: (1) the flare filament, which first arises with the flare; (2) changes in already existing filaments. Extensive statistical results are given on flare filaments for their frequency, position, size, lifetime, and relationship to the importance of the flare. Definite conditions could not be determined for the origin of a flare filament. The rule found by H. W. Newton on the succession of radial velocities is established for 90% of the cases; exceptions are discussed. The time-velocity diagram acquires a simple significance, from the circumstance that the rising filament material, in the neighborhood of the summit of its trajectory, becomes invisible because of too low contrast with the undisturbed chromosphere. The meaning of measured velocities and their changes are described and discussed; the latter, in general, are not to be described as accelerations. Changes occurring in already existing filaments are described by a means of a few examples. (Author)


Descriptors :   *SOLAR ATMOSPHERE , *SOLAR FLARES , ASTROPHYSICS , VELOCITY , VISIBILITY , STATISTICAL ANALYSIS , LIFE EXPECTANCY(SERVICE LIFE)


Subject Categories : Astrophysics


Distribution Statement : APPROVED FOR PUBLIC RELEASE