A complex active-region filament eruption: the event on 2000 February 9

Defang Kong, Yunan Astronomical Observatory

Abstract
We present a multi-wavelength analysis of an active-region filament eruption in NOAA active region(AR) 08858 on February 9, 2000. This event was observed by the space borne instruments of Transition Region and Coronal Explorer(TRACE), Michelson Doppler Imager(MDI) and Large Angle and Spectrometric Coronagraph(LASCO) on board Solar and heliospheric Observatory(SOHO), and Geostationary Operational Environmental Satellite(GOES). Some interesting aspects are found as follows: (1) the appearance of the brightenings in the chromosghere is the precursor of the filament expansion; (2) the eruption of the filament can be divided into four phases;(3) there is a time delay between the velocity peaks of two parts of the bright strands and that of the main filament in the velocity time curves;(4) the overlying magnetic loops and the expansion of the strands that are integral to the filament can change the eruptive direction of the filament. These results are helpful for us to understand the relationship between the eruption of filament and associated flare and CME.