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EIT And SXT Observations of a Quiet-Region Filament Ejection: First Eruption, Then ReconnectionWe observe a slow-onset quiet-region filament eruption with the Extreme Ultraviolet Imaging Telescope (EIT) on the Solar Heliospheric Observatory (SOHO) and the Soft X-ray Telescope (SXT) on Yohkoh. This event occurred on 1999 April 18 and was likely the origin of a coronal mass ejection detected by SOHO at 08:30 UT on that day. In the EIT observation, one-half of the filament shows two stages of evolution: stage 1 is a slow, roughly constant upward movement at approximately 1 km/s lasting approximately 0.5 hr, and stage 2 is a rapid upward eruption at approximately 16 km/s occurring just before the filament disappears into interplanetary space. The other half of the filament shows little motion along the line of sight during the time of stage 1 but erupts along with the rest of the filament during stage 2. There is no obvious emission from the filament in the SXT observation until stage 2; at that time, an arcade of EUV and soft X-ray loops forms first at the central location of the filament and then expands outward along the length of the filament channel. A plot of EUV intensity versus time of the central portion of the filament (where the postflare loops initially form) shows a flat profile during stage 1 and a rapid upturn after the start of stage 2. This light curve is delayed from what would be expected if 'tether-cutting' reconnection in the core of the erupting region were responsible for the initiation of the eruption. Rather, these observations suggest that a loss of stability of the magnetic field holding the filament initiates the eruption, with reconnection in the core region occurring only as a by-product.
Document ID
20020023811
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Sterling, Alphonse C. (NASA Marshall Space Flight Center Huntsville, AL United States)
Moore, Ronald L. (NASA Marshall Space Flight Center Huntsville, AL United States)
Thompson, Barbara J. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
August 20, 2013
Publication Date
November 10, 2001
Publication Information
Publication: Astrophysical Journal
Volume: 561
Subject Category
Astronomy
Distribution Limits
Public
Copyright
Other