LASCO Observations of Disconnected Magnetic Structures Out to Beyond 28 Solar Radii During Coronal Mass Ejections
Abstract
Two coronal mass ejections have been well observed by the LASCO coronagraphs to move out into the interplanetary medium as disconnected plasmoids. The first, on July 28, 1996, left the Sun above the west limb around 18:00 UT. As it moved out, a bright V-shaped structure was visible in the C2 coronagraph which moved into the field-of-view of C3 and could be observed out to beyond 28 solar radii. The derived average velocity in the plane of the sky was 110 plus or minus km s(-1) out to 5 solar radii, and above 15 solar radii the velocity was 269 10 km s(-1). Thus there is evidence of some acceleration around 6 solar radii. The second event occurred on November 5, 1996 and left the west limb around 04:00 UT. The event had an average velocity in the plane of the sky of approx. 54 km s(-1) below 4 R, and it accelerated rapidly around 5 R up to 310 plus or minus 10 km s(-1). In both events the rising plasmoid is connected back to the Sun by a straight, bright ray, which is probably a signature of a neutral sheet. In the November event there is evidence for multiple plasmoid ejections. The acceleration of the plasmoids around a projected altitude of 5 solar radii is probably a manifestation of the source surface of the solar wind.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1997
- Accession Number
- ADA530510
Entities
People
- C. J. Eyles
- D. J. Michels
- D. K. Bedford
- G. E. Brueckner
- G. M. Simnett
- J. D. Moses
- O. C. St. Cyr
- R. A. Howard
- S. J. Tappin
- S. P. Plunkett
Organizations
- University of Birmingham