Abstract
Calculations which predict that a phenomenon analogous to stellar negative pre-flares could also exist on the Sun were published by Hénouxet al. (1990), and Aboudarhamet al., (1990), who showed that 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 disc and on the wavelength band of the observation.
TheYohkoh satellite provided white-light data from the aspect camera of the SXT instrument (Tsunetaet 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.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Aboudarham, J., Hénoux, J.C.: 1986,Astron. Astrophys. 168, 301.
Aboudarham, J. and Hénoux, J.C.: 1987,Astron.Astrophys. 174, 270.
Aboudarham, J. and Hénoux, J.C., Brown, J.C., van den Oord, G.H.J., van Driel-Gesztelyi, L., and Gerlei, O.: 1990,Solar Phys. 130, 577.
Bruevich, V.V. et al.: 1980,Izv. Krim. Astrofiz. Obs. 61, 90.
Carrington, R.C.: 1859,Monthly Not. Roy. Astron. Soc. 20, 13. Cristaldi, S., Gershberg, R.E., Rodonò, M.: 1980,Astron. Astrophys. 89, 123.
Flesch, T.R. and Oliver, J.P.: 1974,Astrophys. J. 189, L127.
Grinin, V.P.: 1973,Izv. Krim. Astrofiz. Obs. 60, 179.
Grinin, V.P.: 1983, ‘’ in in P.B. Byrne and M. Rodonò (eds.), ed(s).,Activity in Red Dwarf Stars, Reidel, Dordrecht, 613.
Hénoux, J.C., Aboudarham, J., Brown, J.C., van den Oord, G.H.J., van Driel-Gesztelyi, L., and Gerlei, O.: 1990,Astron. Astrophys. 233, 577.
Hudson, H.S.: 1972,Solar Phys. 24, 414.
Hudson, H.S., Acton, L.W., Hirayama, T., and Uchida, Y.: 1992,Publ. Astron. Soc. Japan 44, L77.
Hudson, H.S., Strong, K.T., Bennis, B.R., Zarro, D., Inda, M., Kosugi, T., and Sakao, T.: 1993,Astrophys. J. L., (submitted).
Hudson, H.S., van Driel-Gesztelyi, L., and Neidig, D.F.: 1994, , (in preparation).
Kundu, M.R.: 1964,Solar Radio Astronomy, New York: Interscience.
Neidig, D.F. and Cliver, E.W.: 1983,AFGL-TR-83-0257 Enviromental Research Papers, No. 856.
Rodonò, M., Pucillo, M., Sedmak, G., de Biase, G.A.: 1979,Astron. Astrophys. 76, 242.
Uchida, Y., and Hudson, H.S.: 1971,Solar Phys. 26, 414.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Van Driel-Gesztelvi, L., Hudson, H.S., Anwar, B. et al. A Yohkoh search for “black-light flares”. Sol Phys 152, 145–151 (1994). https://doi.org/10.1007/BF01473197
Issue Date:
DOI: https://doi.org/10.1007/BF01473197