HR: 1340h
AN: SH53B-0316    [Abstracts]
TI: Brightness Characteristics of Halo CMEs
AU: * Lara, A
EM: alara@geofisica.unam.mx
AF: Instituto de Geofisica UNAM, Ciudad Universitaria, Mexico DF, 04510 Mexico
AU: Gopalswamy, N
EM: gopals@fugee.gsfc.nasa.gov
AF: NASA/GSFC, Code 695.0 Bldg 21, Room 260, Greenbelt, MD 20771 United States
AU: Michalek, G
EM: michalek@oa.uj.edu.pl
AF: Astronomical Observatory, Jagiellonian University ul. Orla 171, Cracow, 30-244 Poland
AU: Xie, H
EM: hong@lepvax.gsfc.nasa.gov
AF: NASA/GSFC, Code 695.0 Bldg 21, Room 260, Greenbelt, MD 20771 United States
AU: Xie, H
EM: hong@lepvax.gsfc.nasa.gov
AF: The Catholic University of America, Physics Department, Washington DC, 20064 United States
AU: Yashiro, S
EM: yashiro@cdaw.gsfc.nasa.gov
AF: NASA/GSFC, Code 695.0 Bldg 21, Room 260, Greenbelt, MD 20771 United States
AU: Yashiro, S
EM: yashiro@cdaw.gsfc.nasa.gov
AF: The Catholic University of America, Physics Department, Washington DC, 20064 United States
AB: It is generally accepted that halo Coronal Mass Ejections (CMEs) are regular, low latitude, CMEs traveling towards (or away FROM) the observer. The association between halo CMEs and solar energetic particles events (SEPs) and Type II bursts is higher compared to regular CMEs. Halo CMEs are observed up to large heliocentric distances as compared to the regular CMEs. This is somewhat contradictory to the theory of Thomson scattering because the visibility conditions for halo CMEs are rather poor, assuming that the longitudinal widths of halo CMEs are the similar to those of regular CMEs. In this paper, we present some observational characteristics of halo CMEs, such as high brightness at large distances and symmetry in the velocity space. The CMEs were observed by the Solar and Heliospheric Observatory (SOHO) mission's Large Angle and Spectrometric Coronagraph (LASCO). We also present a possible model that explains the apparent contradiction
DE: 7500 SOLAR PHYSICS, ASTROPHYSICS, AND ASTRONOMY
DE: 7513 Coronal mass ejections
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting