HR: 0830h
AN: SM31B-1105 [PDF]
TI: Mass and Speed of the April 21, 2002 CME at 1.64 Solar Radii
AU: * Raymond, J C
EM: jraymond@cfa.harvard.edu
AF: John Raymond, Center for Astrophysics
60 Gardden St., Cambridge, MA 02138
AB:
A partial halo CME was associated with an X-class flare on
April 21, 2002. It accelerated to 2500 km/s and produced
an SEP event. UVCS/SOHO observed the event at 1.64 solar
radii, near the peak acceleration. The UV spectra establish
the conditions in the pre-CME streamer where much of the
mass of the CME originates. Doppler shifts show that a large
part of the streamer motion is transverse rather than radial,
with an Earth-directed velocity component of 850 km/s. The
transverse acceleration is even larger than the radial
acceleration. From the density and acceleration we derive a
lower limit to the magnetic field at 1.64 solar radii. High
temperature emission indicates a probable current sheet,
which in some CME models is vital to the CME acceleration.
Thus we obtain estimates of the mass, acceleration and
magnetic field of the CME in the region of the corona where
these quantities are established.
DE: 7513 Coronal mass ejections
DE: 7549 Ultraviolet emissions
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting