Halo CME Mail Date: Fri, 16 Mar 2001 16:09 From: Gareth Lawrence Subject: Partial Halo CME on 2001/03/16 ------------------------------------------------------------------------ UCMEO 93001 10316 2100/ 10316 60350 90727 2201/ 110// 213// 40213 10315 62036 92236 41001 0//// 3112/ 99999 PLAIN BT LASCO (and EIT) observed a full halo CME on 2001/03/16. The event was first observed in C2 at 03:50 UT, as a bright loop front over the NW limb. At 07:50 this bright front extended from about PA 220 to PA 110. The north-westerly front first appeared in C3 at 05:18. The plane-of-sky speed of the leading edge through to the edge of the C2 field of view was about 213 km/s at PA 318 (W limb) and somewhat slower (approx 198 km/s) through C3. The CME was probably associated with an eruptive filament observed near disk center by EIT between 20:36 and 22:36 UT on 2001/03/15. The center of the region first visibly affected was N01W10 and the greater part of EIT activity appeared somewhat to the W of this, consistent with the first appearance of the CME over the NW limb. This site of origin was beteen AR 9373 and AR 9384. Several small GOES X-ray events were recorded from both active regions between 19:30 and 22:00 UT, the most powerful being a C2.9 flare. However, given the prolonged timeframe of the EIT event, the long transit time to the C2 field of view and the slow plane-of-sky speed through both coronagraphs, it is likely that the filament eruption was the primary source of this event. Images and movies of this event are available at: ftp://ares.nrl.navy.mil/pub/lasco/halo/20010316. Best wishes, Gareth Lawrence. ++ | Gareth Lawrence, E-mail:grl@ajcannon.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 G-1, +1-301-286-3447 | | Greenbelt, MD 20771. Fax: +1-301-286-0264 | ++