Abstract
We present Hα and coronal X-ray images of the large two-ribbon flare of 25–26 June, 1992 during its long-lasting gradual decay phase. From these observations we deduce that the 3-D magnetic field configuration late in this flare was similar to that at and before the onset of such large eruptive bipolar flares: the sheared core field running under and out of the flare arcade was S-shaped, and at least one elbow of the S looped into the low corona. From previous observations of filament-eruption flares, we infer that such core-field coronal elbows, though rarely observed, are probably a common feature of the 3-D magnetic field configuration late in large two-ribbon flares. The rare circumstance that apparently resulted in a coronal elbow of the core field being visible in Hα in our flare was the occurrence of a series of subflares low in the core field under the late-phase arcade of the large flare; these subflares probably produced flaring arches in the northern coronal elbow, thereby rendering this elbow visible in Hα. The observed late-phase 3-D field configuration presented here, together with the recent sheared-core bipolar magnetic field model of Antiochos, Dahlburg, and Klimchuk (1994) and recent Yohkoh SXT observations of the coronal magnetic field configuration at and before the onset of large eruptive bipolar flares, supports the seminal 3-D model for eruptive two-ribbon flares proposed by Hirayama (1974), with three modifications: (1) the preflare magnetic field is closed over the filament-holding core field; (2) the preflare core field has the shape of an S (or backward S) with coronal elbows; (3) a lower part of the core field does not erupt and open, but remains closed throughout flare, and can have prominent coronal elbows. In this picture, the rest of the core field, the upper part, does erupt and open along with the preflare arcade envelope field in which it rides; the flare arcade is formed by reconnection that begins in the middle of the core field at the start of the eruption and progresses from reconnecting closed core field early in the flare to reconnecting ‘opened’ envelope field late in the flare.
Similar content being viewed by others
References
Antiochos, S. K, Dahlburg, R. B., and Klimchuk, J. A.: 1994, Astrophys. J. 420, L41.
Dodson-Prince, H. W. and Bruzek, A.: 1977, in in A. Bruzek and C. J. Durrant (eds.), Illustrated Glossary for Solar and Solar-Terrestrial Physics, D. Reidel Publ. Co., Dordrecht, Holland, p. 81.
Fontenla, J. M., Švestka, Z., Fárník, F., and Tang, F. Y.: 1991, Solar Phys. 134, 145.
Gary, G. A., Moore, R. L., Hagyard, M. J., and Haisch, B. M.: 1987, Astrophys. J. 314, 782.
Hirayama, T.: 1974, Solar Phys. 34, 323.
Hudson, H. S., Acton, L. W., and Freeland, S. L.: 1996, Astrophys. J. 470, 629.
Malherbe, J.M., Tarbell, T., Wiik, J. E., Schmieder, B., Franck, Z., Shine, R., and van Driel-Gesztelyi, L.: 1997, Astrophys. J. 482, in press.
Manoharan, P. K., van Driel-Gesztelyi, L., Pick, M., and Démoulin, P.: 1996, Astrophys. J. 468, L73.
Martin, S. F. and Š vestka, Z. F.: 1988, Solar Phys. 116, 91.
Martin, S. F., Bilimoria, R., and Tracadas, P.W.: 1994, in R. J. Rutten and C. J. Schrijver (eds.), Solar Surface Magnetism, Springer-Verlag, Berlin, p. 303.
Moore, R. L., and LaBonte, B. J.: 1980, in M. Dryer and E. Tandberg-Hanssen (eds.), Solar and Interplanetary Dynamics, D. Reidel Publ. Co., Dordrecht, Holland, p. 207.
Moore, R. L. and Roumeliotis, G.: 1992, in Z. Švestka, B. V. Jackson, and M. E. Machado (eds.), Eruptive Solar Flares, Springer-Verlag, Berlin, p. 69.
Moore, R. L., LaRosa, T. N., and Orwig, L. E.: 1995, Astrophys. J. 438, 985.
Moore, R., McKenzie, D. L., Švestka, Z., Widing, K. G. et al.: 1980, in P. A. Sturrock (ed.), Solar Flares, Colorado Associated University Press, Boulder, Colorado, p. 341.
Moore, R. L., Hudson, H. S., Lemen, J. R., Shibata, K., Hirayama, T., and Ogawara, Y.: 1996, oral and poster presentation at Workshop on Measurements and Analyses of the 3-D Solar Magnetic Fields, held in Huntsville, Alabama, 9-11 April 1996, in preparation for publication.
Pevtsov, A. A., Canfield, R. C., and Metcalf, T. R.: 1995, Astrophys. J. 440, L109.
Pevtsov, A. A., Canfield, R. C., and Zirin, H.: 1996, Astrophys. J. 473, 533.
Rust, D. M. and Kumar, A.: 1996, Astrophys. J. 464, L199.
Schmieder, B., Démoulin, P., Aulanier, G., and Golub, L.: 1996a, Astrophys. J. 467, 881.
Schmieder, B., Heinzel. P., van Driel-Gesztelyi, L., and Lemen, J. R.: 1996b, Solar Phys. 165, 303.
Shibata, K.: 1996, in Y. Uchida, T. Kosugi, and H. S. Hudson (eds.), Proc. IAU Colloq. 153, 13.
Švestka, Z., and Cliver, E.W.: 1992, in Z. Švestka, B. V. Jackson, and M. E. Machado (eds.), Eruptive Solar Flares, Springer-Verlag, Berlin, p. 1.
Švestka, Z. F., Fárník, F., Fontenla, J. M., and Martin, S. F.: 1989, Solar Phys. 123, 317.
Tang, F.: 1986, Solar Phys. 105, 399.
Tsuneta, S.: 1996, in Y. Uchida, T. Kosugi, and H. S. Hudson (eds.), Proc. IAU Colloq. 153, 161.
Tsuneta, S., Hara, H., Shimizu, T., Acton, L.W., Strong, K. T., Hudson, H. S., and Ogawara, Y.: 1992, Publ. Astron. Soc. Japan 44, L63.
van Driel, L., Wiik, J. E., Schmieder, B., Tarbell, T., Kitai, R., Funakoshi, Y., and Anwar, B.: 1997, Solar Phys., in press.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Moore, R.L., Schmieder, B., Hathaway, D.H. et al. 3-D Magnetic Field Configuration Late in a Large Two-Ribbon Flare. Solar Physics 176, 153–169 (1997). https://doi.org/10.1023/A:1004990817154
Issue Date:
DOI: https://doi.org/10.1023/A:1004990817154