Halo CME Mail Date: Mon, 3 Feb 2003 17:11 From: Gareth Lawrence Subject: Partial Halo CME on 2003/02/01, possibly fronsided ------------------------------------------------------------------------ UCMEO 93001 30203 2215/ 30201 60939 90845 2551/ 040// 222// 40589 ///// ///// ///// ///// ///// ///// 99999 PLAIN BT LASCO observed a possible partial halo CME on 2003/02/01. The event was first observed in C2 at 01:51 UT as ragged loop front systems over the NW limb and N pole a significant way into C2's field of view. The two systems appear distinct but there is insufficient data to rule out the possiblility of a connection. The total span of the system is about 145 deg, from PA 255 - 40. These fronts first appeared in C3 at 02:20 UT but additionally with evidence of a leading edge some way ahead of the NW limb fronts only. The mean plane-of-sky speed for the system was 589 km/s at PA 282, with insufficient data to infer acceleration, or lack thereof. Only C3 data were used to measure this speed. EIT had begun a routine CCD bakeout by this time, so no on-disk EUV data are available. However, GOES recorded a Type II radio burst from 22:09 UT on 2003/01/31 which could have been associated with a frontsided source. In light of the ambiguity in the data we conclude there is a possibility that this event has an earthward-directed component. Movies and images of this event are available now at: ftp://ares.nrl.navy.mil/pub/lasco/halo/20030131 Some people may experience difficulties obtaining the images and movies at present; this is due to unresolved issues with the firewall at NRL. Aplogies to those affected; the problem is being worked on. Best wishes, Gareth Lawrence. ++ | Gareth Lawrence, E-mail:grl@kreutz.nascom.nasa.gov | | SOHO-LASCO Operations Scientist, | | CUA, Mail Code 682.3, | | NASA Goddard Space Flight Center, Phone: +1-301-286-2941 | | Building 26, Room 001, +1-301-286-3447 | | Greenbelt, MD 20771. Fax: +1-301-286-0264 | ++