Observations of preburst heating and magnetic field changes in a coronal loop at 20 cm wavelength
✍ Scribed by Robert F. Willson
- Publisher
- Springer
- Year
- 1984
- Tongue
- English
- Weight
- 731 KB
- Volume
- 92
- Category
- Article
- ISSN
- 0038-0938
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✦ Synopsis
The Very Large Array (VLA) has been used at 20 cm wavelength to study the evolution of a burst loop with 4" resolution on timescales as short as 10 s. The VLA observations show that the coronal loop began to heat up and change its structure about 15 rain betbre the eruption of two impulsive bursts. The first of these bursts occurred near the top of the loop that underwent preburst heating, while the second burst probably occurred along the legs of an adjacent loop. These observations evoke flare models in which coronal loops twist, develop magnetic instabilities and then erupt. We also combine the VLA observations with GOES X-ray data to derive a peak electron temperature of 1~. = 2.5 x 10 7 K and an average electron density of .u ~ 1 x 10 TM cm :~ il'l the coronal loop during tile preburst heating phase.