A YOHKOH search for `black-light flares'

Details A YOHKOH search for `black-light flares' A YOHKOH search for `black-light flares'

Jun 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994soph..152..145v&link_type=abstract

Solar Physics (ISSN 0038-0938), vol. 152, no. 1, p. 145-151

Physics

8

Electron Beams, Photosphere, Position (Location), Solar Flares, Variability, Japanese Spacecraft, Solar Activity Effects, X Ray Telescopes

Scientific paper

Calculations which predict that a phenomenon analogous to stellar negative pre-flares could also exist on the Sun were published by Henoux et al. (1990), and Aboudarham et al., (1990), who showed at the beginning of a solar white-light flare (WLF) event an electron beam can cause a transient darkening before the WLF emission starts, under certain conditions. They named this event a `black light flare' (BLF). Such a BLF event should appear as diffuse dark patches lasting for about 20 seconds preceding the WLF emission, which would coincide with intense and impulsive hard X-ray bursts. The BLF location would be at (or in the vicinity of ) the forthcoming bright patches. Their predicted contrast depends on the position of the flare on the solar disk and on the wavelength band of the observation. The Yohkoh satellite provided white-light data from the aspect camera of the Soft X-ray Telescope (SXT) instrument (Tsuneta et al., 1991), at 431 nm and with a typical image interval of 10 - 12 s. We have studied nine white-light flares observed with this instrument, with X-ray class larger than M6. We have found a few interesting episodes, but no unambiguous example of the predicted BLF event. This study, although the best survey to date, was not ideal from the observational point of view. We therefore encourage further searches. Successful observations of this phenomenon on the Sun would greatly strengthen our knowledge of the lower solar atmosphere and its effects on solar luminosity variations.

Affiliated with

Also associated with

No associations

Rating

A YOHKOH search for `black-light flares' does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A YOHKOH search for `black-light flares', we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A YOHKOH search for `black-light flares' will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1508515