Halo CME Mail Date: Tue, 23 Oct 2001 13:44 From: Gareth Lawrence Subject: Partial Halo CME on 2001/10/22 ------------------------------------------------------------------------ UCMEO 93001 11022 1800/ 11022 61826 92342 0721/ 264// 213// 40621 11022 61748 91824 21618 09672 1222/ 99999 PLAIN BT LASCO and EIT observed a partial halo CME on 2001/10/22. The event was first observed in C2 at 18:26 UT as a bright loop front over the SE limb; by 18:50 UT front spanned about 190 deg around the C2 occulting disk from PA 72 to PA 264. The front first appeared unambiguously in C3 at 19:42 UT with maximal coverage of the C3 occultor by 20:18 UT. The plane of sky speed of the front was measured as 621 km/s at PA 123 (SE) with moderate deceleration through the coronagraphs' fields of view. The CME was most probably associated with an X1.2 X-ray flare in AR9672 between 17:43 and 18:09 UT with peak emission at 17:51 UT. EIT observed this flare between 17:48 and 18:24 UT, with peak emission at 18:00 UT. SEC places the flare at S18E16. Neither an EIT wave nor a dimming was observed in association with this event. Images and movies of this event are available at: ftp://ares.nrl.navy.mil/pub/lasco/halo/20011022b and note that an earler, brighter full halo CME is clearly visible in the C3 movies. Finally, to clarify a point in the last report, where it reads, "An EIT wave dimming was observed in association with this event, but no dimming." this should read "An EIT wave was observed in association with this event, but no dimming." Apologies for the confusion. 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 G-1, +1-301-286-3447 | | Greenbelt, MD 20771. Fax: +1-301-286-0264 | ++