𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Spectrograph, filtergraph and magnetograph observations of the two-ribbon flare of 29 July, 1973

✍ Scribed by A. G. Michalitsanos; P. Kupferman


Publisher
Springer
Year
1974
Tongue
English
Weight
875 KB
Volume
36
Category
Article
ISSN
0038-0938

No coin nor oath required. For personal study only.

✦ Synopsis


We present high resolution detailed observations of the class 3N two-ribbon flare of 1973, July 29 (McMath 12461), which was associated with the disappearance of a large filament ('disparition brusque'). This flare occurred in a diffuse bipolar magnetic region completely devoid of sunspots, and was further associated with a type IV radio burst and a soft X-ray event. Extensive Ha filtergraph, spectrograph and magnetograph records during the main phase of the flare suggest that downfalling and streaming material is present on both ribbons for several hours during the Ha emission enhancement, but only at a small number of points located both on and off the ribbons. We find a poor spatial correspondence between bright emission knots in the Ha ribbons and the positions of the observed downward motion. We conclude that the model of infall-impact of Hyder (1967a, b) is not consistent with our filtergraph and spectrograph observations.