Abstract
We analyse the physical characteristics of a C5.7 class flare which was observed on 27 September, 1993 using data from the soft X-ray telescope (SXT), the Bragg crystal spectrometer (BCS), and the hard X-ray telescope (HXT) on Yohkoh. The flare takes the form of a simple loop which is much brighter at one of its footpoints than anywhere else for a period of 2 min. During this time there is an increase in the soft X-ray fluxes, and a corresponding peak in hard X-rays. The parameters derived from the hard X-ray and soft X-ray spectra and images are assumed to be from the footpoint. This flare showed two peaks in the non-thermal velocity, the first one simultaneous with the footpoint brightening. The non-thermal velocity corresponding to these first few minutes is unusually large – by a factor of 80%, 68%, and 26% relative to the second peak in the Fexxv, Caxix, and Sxv channels respectively.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Acton, L. W., Feldman, U., Bruner, M. E., Doschek, G. A., Hirayama, T., Hudson, H. S., Lemen, J. R., Ogawara, Y., Strong, K. T., and Tsuneta, S.: 1992, Publ. Astron. Soc. Japan 44, L71.
Antonucci, E., Benna, C., and Somov, B. V.: 1996, Astrophys. J. 456, 833.
Culhane, J. L. et al.: 1991, Solar Phys. 136, 89.
Culhane, J. L. et al.: 1994, Solar Phys. 153, 307.
Doschek, G. A. and Feldman, U.: 1987, Astrophys. J. 313, 883.
Doschek, G. A. et al.: 1986, The Solar Maximum Mission Workshop Proceedings, NASA Conference Publication 2439, Chapter 4.
Feldman, U., Doschek, G. A., Kreplin, R. W., and Mariska, J. T.: 1980, Astrophys. J. 241, 1175.
Feldman, U., Hiei, E., Phillips, K. J. H., Brown, C. M., and Lang, J.: 1994, Astrophys. J. 421, 843.
Forbes, T. G. and Malherbe, J. M.: 1991, Solar Phys. 135, 361.
Harra-Murnion, L. K. et al.: 1996, Astron. Astrophys. 308, 670.
Heyvaerts, J., Priest, E. R., and Rust, D. M.: 1977, Astrophys. J. 216, 123.
Hudson, H. S, Strong, K. T., Dennis, B. R., Zarro, D., Inda, M., Kosugi, T., and Sakao, T.: 1994, Astrophys. J. 422, L25.
Khan, J. I., Harra-Murnion, L. K., Hudson, H. S., Lemen, J. R., and Sterling, A. C.: 1995, Astrophys. J. 452, L153.
Kosugi, T. et al.: 1991, Solar Phys. 136, 17.
Kosugi, T., Sakao, T., Masuda, S., Hara, H., Shimizu, T., and Hudson, H. S.: 1994, Proc. of Kofu Symposium, NRO Report No. 360.
Lang, J., Brown, C. M., Magraw, J. E., and Payne, J.: 1993, RAL report.
Mariska, J. T.: 1994, Astrophys. J. 434, 756.
Mariska, J. T., Sakao, T., and Bentley, R. D.: 1996, Astrophys. J. 459, 815.
Metcalf, T. R., Hudson, H. S., Kosugi, T., Puetter, R. C., and Piña, R. K.: 1996, Astrophys. J., in press.
Nitta, N., Yaji, K., and Hudson, H. S.: 1996, in preparation.
Neupert, W.: 1968, Astrophys. J. 153, L59.
Piña, R. K. and Puetter, R. C.: 1993, Publ. Astron. Soc. Japan 105, 630.
Sterling, A. C.: 1994, Proc. of Kofu Symposium, NRO Report No. 360.
Sterling, A. C., Harra-Murnion, L. K., Hudson, H. S., and Lemen, J. R.: 1996, Atrophys. J. 464, 498.
Trow, T. W., Bento, A. C., and Smith, A.: 1994, Nucl. Instr. Methods Phys. Res. A 348, 252.
Tsuneta, S.: 1995, Publ. Astron. Soc. Japan 47, 691.
Tsuneta, S.: 1996, Astrophys. J., 456, 840.
Tsuneta, S. et al.: 1991, Solar Phys. 136, 37.
Tsuneta, S. et al.: 1992, Publ. Astron. Soc. Japan 44, L63.
Wülser, J.-P. et al.: 1994, Astrophys. J. 424, 459.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
HARRA-MURNION, L.K., CULHANE, J.L., HUDSON, H.S. et al. ISOLATING THE FOOTPOINT CHARACTERISTICS OF A SOLAR FLARE LOOP. Solar Physics 171, 103–122 (1997). https://doi.org/10.1023/A:1004903027543
Issue Date:
DOI: https://doi.org/10.1023/A:1004903027543