Abstract
We describe visual observations of a white light flare which displayed a pink color in a part of the flare which covered a sunspot umbra. We then show that visible pink tint, if attributable to strong Hα emission, requires a minimum equivalent emission line width of approximately 140 A, or three times larger than in any flare previously measured. Such extreme line broadening might be interpreted to result from flare penetration to unusually high chromospheric densities (≳ 1014 cm−3), or from anomalous Stark broadening due to turbulent electric fields in an unstable plasma (Spicer and Davis, 1975) at lower density.
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References
Bakshi, P. and Kalman, G.: 1976, Solar Phys. 47, 307.
Martheray, M.: 1922, Astronomie 36, 276.
Neidig, D. F.: 1978, Solar Phys. 57, 385.
Slonim, Y. M. and Korobova, Z. B.: 1975, Solar Phys. 40, 397.
Smith, H. J. and Smith, E. v. P.: 1963, Solar Flares, MacMillan, New York.
Spicer, D. S. and Davis, J.: 1975, Solar Phys. 43, 107.
Švestka, Z.: 1966, Space Sci. Rev. 5, 388.
Švestka, Z.: 1976, Solar Flares, D. Reidel Publ. Co., Dordrecht, Holland.
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Operated by the Association of Universities for Research in Astronomy, Inc., under contract with the National Science Foundation.
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Neidig, D.F., Beck, R.O. On the color of the 26 February 1981 white light flare. Sol Phys 78, 225–228 (1982). https://doi.org/10.1007/BF00151605
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DOI: https://doi.org/10.1007/BF00151605