fl163.dejager01 Posted: 12-Dec-93 Updated: 12-Aug-94, 13-May-95 Events specified: Flare on 2-Aug-93 at 08:28 UT
Cornelis de Jager[1], Mika Inda-Koide[2], Shinji Koide[3], and Jun-ichi Sakai[3]
[1] Space Research Laboratory, Sorbonnelaan 2, 3584, CA Utrecht , The Netherlands. [2] Department of Astronomy, Faculty of Science,University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan 113. Laboratory for Plasma Astrophysics and Fusion Science, Department of Electronics and Information, Faculty of Engineering, Toyama University, Toyama, 930, Japan. [3] Laboratory for Plasma Astrophysics and Fusion Science, Department of Electronics and Information, Faculty of Engineering, Toyama University, Toyama, 930, Japan.
Abstract:
The limb-flare of August 2, 1993 08:28 UT ( GOES classification B6.8 ) originated in the process of X-type reconnection. A comparison of the observation with a comparison of the radiated energy with that available in the azimuthal field component, yield construct agreement if it is assumed that the flare loops have a filamentary structure with an azimuthal field component of about 40 gauss and a filling factor of about 1 to 2 %.
Update 13-May-95
The work has been finished, and the paper will be published in Solar Physics. So, the project can be closed.
paper: Ongoing partial reconnection in a limb flare authors: C. de Jager, M. Inda-Koide, S. Koide, J.I. Sakai
abstract: The limb flare of August 2, 08:30 UT, consisting of two crossed loops, shows evidence of partial X-type reconnection. The observations suggest that partial reconnection was an ongoing process during about 10 min until flare ignition.
Update 12-Aug-94
C. de Jager, M. Inda-Koide, S. Koide and J.I. Sakai: Multiple X-type interaction in a small solar limb flare observed by YOHKOH.
Abstract: The study of the limb flare on August 2, 1993 (GOES classification B6.8), consisting of two crossing loops, shows that X- type partial reconnection is in this flare an ongoing process during some 20 minutes; it gradually leads to flaring. After some ten minutes of precursor activities two crossing loops became gradually visible on YOHKOH soft X-ray images. They reached maximum brightness on 08:28 UT. Simultaneously, an X-ray flare originated at the crosspoint of the loops and it reached maximum brightness at 08:30.4 UT. We compared these observations with results from X-type reconnection theory, while also including a comparison of the radiated energy with the magnetic energy content of the azimuthal field component. Consistent agreement between the observations and theory was obtained by assuming - in agreement with theoretical expectations - that the flare loop had a filamentary ('fluxthread') helical structure, with an azimuthal fieldstrength component of about 40 to 100 gauss, and a
filling factor of ca. 0.01. The apparent interaction between the loops must have had the characted of partial reconnection, which means that only the poloidal component of the fields coalesced. The observations suggest that partial reconnection between the fluxthreads occurredduring 20 - 25 minutes from about 08:10 UT onward. The hot, dense plasma that thus originated was a manifestation of enhanced current density, leading to increased fluxloop instability until flare outburst.
submitted: Solar Physics