Halo CME MailHalo CME Mail Date: Tue, 4 Nov 2003 17:15 From: Gareth Lawrence Subject: Full Halo CME on 2003/11/04, frontsided UCMEO 93001 31104 2130/ 31104 61954 82042 0001/ 360// 233// 42381 31104 61936 92012 38822 10486 1111/ 99999 PLAIN BT LASCO and EIT observed a full halo CME on 2003/11/04. The event was first observed in C2 at 19:54 UT as a bright loop front in the SE; by 20:06 UT the front had developed into a full halo CME, though rather faint in the NE. The front first appeared in C3 images at 20:18 UT with full coverage of the C3 occulting disk by 20:42 UT. The mean plane-of-sky speed for this event was 2381 km/s at PA 247; there is possible evidence for moderate acceleration though at the time of writing only four data point are available so this may be an artefact of the sparse data. The CME was probably associated with an X18+ X-ray flare observed by EIT between 19:36 - 20:12 UT, centered at S22W88 with peak emission at 19:48 UT. GOES records this flare from AR 0486 between 19:29 - 20:07 UT with a prolonged saturated peak between ~19:40 - ~19:55 UT. A large EIT wave, and dimming, were observed in association with this event. This event has therefore been determined frontsided. Movies and images of this event will shortly be available at: ftp://ares.nrl.navy.mil/pub/lasco/halo/20031104 and the EIT movies in particular are truly spectacular! Best wishes, Gareth Lawrence. +----------PLEASE NOTE NEW EMAIL ADDRESS-----------+ Gareth Lawrence, grl@grace.nascom.nasa.gov SOHO-LASCO Operations Scientist, CUA, MC 682.3, Bldg 26, Rm 001, F: +1-301-286-0264 NASA Goddard Space Flight Center, Greenbelt, MD 20771. P: +1-301-286-2941 ++