Analysis of evolution of NOAA 7912 active region on 19 October 1995

Citation
P. Rudawy et al., Analysis of evolution of NOAA 7912 active region on 19 October 1995, ASTR AST SS, 139(1), 1999, pp. 89-96
Citations number
17
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES
ISSN journal
03650138 → ACNP
Volume
139
Issue
1
Year of publication
1999
Pages
89 - 96
Database
ISI
SICI code
0365-0138(199910)139:1<89:AOEON7>2.0.ZU;2-0
Abstract
An analysis of a minor (B3.2) flare related to an X-ray jet in the reversed polarity NOAA 7912 active region is presented, focusing on various kinds o f activity observed in the H alpha line with the MSDP instrument. Using com plementary Yohkoh soft X-ray observations and a Kitt Peak magnetic field ma p we study the influence of a rather low and graduate energy release on fil aments, fibrils and chromospheric brightenings and their relevant coronal f eatures. We find that this small flare affected the entire AR and was assoc iated with strong up- and downflows along remote fibrils and filaments, whi ch appear to be connected by large-scale loops. It is shown that at least o ne of the observed brightenings was caused by downflow of the matter, thus, by the kinematic heating of the material. The filament in the vicinity of the hare footpoints changed the most: it broke into two parts, temporarily rose to higher altitudes inside the AR and even erupted outside of the AR, re-forming only three hours later. We show that even a minor flare can lead to important morphological and dynamical changes in an active region.