Subject: SOHO/LASCO Partial HALO CME 100228 - Backsided UCMEO 93001 00229 2220/ 00228 61254 80042 2612/ 073// 123// 40415 00228 61236 82224 1//// ///// 3222/ 99999 PLAIN SOHO/LASCO observed a partial HALO CME (type P) on February 28, 2010. Event began in C2 at 12:54 UT as a wide symmetric slow loop front over the North Pole, centered approximately at PA 350 degrees. This CME progressed to an active multiloop with core and scattered bulk materials as it expands with material eventually seen from PA 261 - 73 for a total coverage of 172 degrees. By 18:54 UT a burst comes over the NE at PA 70 degrees followed byan asymmetric loop with core(s). This could possibly be a shock event disturbed by the 12:54 UT halo. The event continues into the C3 field beginning at 16:18 UT over the North Pole and measured through the field as the event ends at approximately 3/1 00:42 UT to 27 Rsun. Time/height measurements were marked to 30 points and calculated to velocities of this event averaging 415.6 Km/sec at position angle 340 degrees through C2 and C3. EIT sees a slow farside CME beginning at 12:36 - 22:24 UT in the NE centered at PA 30 degrees. This most possibly pertains to the event seen in LASCO. This event is determined a BACKSIDED HALO event. LASCO images, movies and time/height information for this event is available on the web at: http://umbra.nascom.nasa.gov/lasco/observations/halo/2010/100228 Best regards, Kevin Schenk SOHO Mission EIT and LASCO Operations NASA-Goddard Space Flight Center, USA BT