Abstract
We analyzed the monochromatic Hα and spectral (within a range of 6549–6579 Å) observational data for the 2B/X6.9 flare of August 9, 2011, that produced emission in the optical continuum. The morphology and evolution of the Hα flare and the position, time evolution, spectrum, and energetics of the white-light flare (WLF) kernels were studied. The following results were obtained: the flare erupted in the region of collision of a new and rapidly growing and propagating magnetic flux and a preexisting one. This collision led to a merger of two active bipolar regions. The white-light flare had a complex structure: no less than five kernels of continuum emission were detected prior to and in the course of the impulsive flare phase. Preimpulsive and impulsive white-light emission kernels belonged to different types (types II and I, respectively) of white-light flares. A close temporal agreement between the white-light emission maxima and the microwave emission peak was observed for the impulsive white-light emission kernels. The maximum flux, luminosity, and total energy emitted by the brightest impulsive WLF kernel equaled 1.4 × 1010 ergs cm−2 s−1, 1.5 × 1027 ergs/s, and 5 × 1029 ergs, respectively. The Hα profiles within the impulsive WLF kernels had broad wings (with a total extent of up to 26 Å and a half-width of up to 9 Å) and self-reversed cores. The profiles were symmetrical, but were shifted towards the red side of the spectrum. This is indicative of a downward motion of the entire emitting volume with a radial velocity of several tens of km/s. The intensity pattern in the wings did not correspond to the Stark one. The profiles were broadened by nonthermal turbulent motions with velocities of 150–300 km/s. The observed Hα profiles were analyzed and compared in their features to the profiles calculated for an intense heating of the chromosphere by nonthermal electrons accompanied by the development of a chromospheric condensation propagating downward. We came to the conclusion that the analyzed flare exhibited spectral features that may not be readily explained within the framework of chromosphere heating by a beam of nonthermal electrons.
Similar content being viewed by others
References
Babin, A.N. and Koval’, A.N., Izv. Krym. Astrofiz. Obs., 1992, vol. 86, p. 152.
Babin, A.N. and Koval’, A.N., Izv. Krym. Astrofiz. Obs., 1993, vol. 88, p. 60.
Babin, A.N., Baranovskii, E.A., Koval’, A.N., Kalman, B., and Gerlei, O., Kinematika Fiz. Nebesnykh Tel, 1998, vol. 14, no. 4, p. 330.
Babin, A.N. and Koval’, A.N., Kinematika Fiz. Nebesnykh Tel, 1999, vol. 15, no. 1, p. 51.
Babin, A.N. and Koval’, A.N., Izv. Krym. Astrofiz. Obs., 2005, vol. 101, p. 107.
Babin, A.N. and Koval’, A.N., Bull. Crimean Astrophys. Observatory, 2007, vol. 103, no. 1, p. 63.
Babin, A.N. and Koval’, A.N., Bull. Crimean Astrophys. Observatory, 2008, vol. 104, no. 1, p. 7.
De la Beaujardiere, J.-F., Canfield, R.C., Metcalf, T.R., et al., Sol. Phys., 1994, vol. 151, p. 389.
Canfield, R.C., Gunkler, T.A., and Ricchiazzi, P.J., Astrophys. J., 1984, vol. 282, p. 296.
Canfield, R.C. and Gayley, K.G., Astrophys. J., 1987, vol. 322, p. 999.
Ding, M.D., Fang, C., Gan, W.R., and Okamoto, T., Astrophys. J., 1994, vol. 429, p. 890.
Fang, C. and Ding, M.D., Astron. Astrophys., Suppl. Ser. 1995, vol. 110, p. 99.
Gaizauskas, V., Harvey, K.L., Harvey, J.W., and Zwan, C., Astrophys. J., 1983, vol. 265, p. 1056.
Gaizauskas, V., Sol. Phys., 1989, vol. 121, p. 135.
Gan, W.Q., Acta Astron. Sin., 1997, vol. 38, p. 394.
Gan, W.Q., Henoux, J.-C., and Faug, C., Astron. Astrophys., 2000, vol. 354, p. 691.
Gopasyuk, S.I., Izv. Krym. Astrofiz. Obs., 1964, vol. 32, p. 14.
Koval’, A.N., Izv. Krym. Astrofiz. Obs., 1965, vol. 33, p. 138.
Koval’, A.N., Izv. Krym. Astrofiz. Obs., 1974, vol. 51, p. 13.
Machado, E.M., Avrett, E.H., Falciani, R., et al., White light flares and atmospheric modeling, The Lower Atmosphere of Solar Flares. Proceedings of the Solar Maximum Mission Symposium (Sunspot, 1985), Sunspot: National Solar Observatory, 1986, p. 483.
Makarova, E.A., Kharitonov, A.V., and Kazachevskaya, T.V., Potok solnechnogo izlucheniya (Solar Radiation Flux), Moscow: Nauka, 1991.
Matthews, S.A., Van Driel-Gestelyi, L., Hudson, H.S., and Nitta, N.V., Astron. Astrophys., 2003, vol. 409, p. 1107.
Neidig, D.F. and Kliver, E.W., Sol. Phys., 1983, vol. 88, p. 275.
Neidig, D.F., Sol. Phys., 1989, vol. 121, p. 261.
Neidig, D.F., Kiplinger, A.L., Cohl, H.S., and Wiborg, P.H., Astrophys. J., 1993, vol. 416, p. 306.
Oliveros, J.-C.M., Hudson, H.S., Hurford, G.J., et al., Astrophys. J., Lett. 2012, vol. 753, L26.
Rieger, E. and Gan, W.Q., Acta Astron. Sin, 1993, vol. 34, p. 430.
Slonim, Yu.M. and Korobova, Z.B., Sol. Phys., 1975, vol. 40, p. 397.
Zirin, H. and Liggett, M.A., Sol. Phys., 1987, vol. 113, p. 267.
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © A.N. Babin, A.N. Koval’, 2013, published in Izvestiya Krymskoi Astrofizicheskoi Observatorii, 2013, Vol. 109, pp. 13–23.
About this article
Cite this article
Babin, A.N., Koval’, A.N. Observational characteristics of the white-light flare of August 9, 2011. Bull.Crim. Astrophys. Observ. 110, 105–113 (2014). https://doi.org/10.3103/S0190271714010057
Received:
Published:
Issue Date:
DOI: https://doi.org/10.3103/S0190271714010057