Halo CME MailHalo CME Mail Date: Wed, 12 Nov 2003 19:58 From: Gareth Lawrence Subject: 'Full' Halo CME on 2003/11/11, frontsided UCMEO 93001 31111 0000/ 31111 61354 91818 0001/ 360// 223// 41383 31111 61336 91348 36203 10498 1222/ 99999 PLAIN BT LASCO and EIT observed a 'full' halo CME on 2003/11/11. A wide bright loop front was seen in C2 at 13:54 UT in the W; however, the next C2 image was not until 15:30 UT by which time the CME was clear of the C2 field of view. The full halo CME first appeared in C3 images at 15:18 UT with bright emission between PA 190-350 and fainter emission around the rest of the occulting disk. Note that the emission in the E is faint and is soon obscured by a separate CME from the E limb/backside. The mean plane-of-sky speed was 1383 km/s, measured at PA 260 with possible evidence for slight acceleration. The CME was probably associated with a M1.6 X-ray flare which EIT observed between 13:36 - 13:48 UT with peak emission at 13:48 UT. The flare was centered at S03W62. Note that EIT observations of the flare are curtailed by subsequent subfield images away from the flare site. SEC records the flare between 13:21 - 14:17 UT with peak emission at 13:51 UT, from AR 0498 located S03W61. It was not possible to clearly identify an EIT wave or dimming in association with this event due to the shortcomings of the data set. Images and movies will shortly be made available at ftp://ares.nrl.navy.mil/pub/lasco/halo/20031111 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 ++