Halo CME MailHalo CME Mail Date: Thu, 20 Nov 2003 17:41 From: Gareth Lawrence Subject: 'Full' Halo CME on 2003/11/18, frontsided UCMEO 93001 31120 2100/ 31120 60806 91718 0001/ 360// 213// 40547 31120 60736 90812 40803 10501 1112/ 99999 PLAIN BT NOTE: this message is being resent due to the original being curtailed and sent without a subject LASCO and EIT observed a 'full' halo CME on 2003/11/20. A ragged loop front was seen in C2 at 08:06 UT in the SE and by 08:26 UT this front had faint extensions surrounding the C2 occultor. From 08:50 UT onwards the event was only clearly visible spanning ~160 deg from the SE to NW. The bright front first appeared in C3 images in the SE at 08:42 UT with faint extension towards the N pole and over the S pole. The mean plane-of-sky speed was 547 km/s, measured at PA 253 with no strong evidence for any acceleration. The CME was probably associated with a M9.6 X-ray flare which EIT observed between 07:36 - 08:12 UT, centered N03W08 and with peak activity at 07:48 UT. Additionally, a filament channel to the S of the active region was activated and subsequently erupted. SEC records the flare between 07:35 - 07:53 UT from AR 0501. A modest EIT wave and slight dimming were observed in association with this event. This event has therefore been determined frontsided. Images and movies will shortly be made available at ftp://ares.nrl.navy.mil/pub/lasco/halo/20031120 Also, please note a typo in the last halo CME report, dated 2003/11/18. In the text it stated first that the flare originated in AR 0501, and later from AR 0498. Only AR 0501 was associated with this event. Apologies for any confusion. 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 ++