UCMEO 93001 50115 1810/ 50115 62306 80618 0001/ 360// 223// 22890 50115 62225 82331 40515 10720 1122/ 99999 PLAIN BT This is the report corresponding to the second 'Full' Halo event launched on 2005/01/15 observed by LASCO/EIT. The event was first seen in C2 at 23:06 UT, as a very bright loop front covering practically the whole NW quadrant. The next C2 frame (23:30 UT) shows the C2 occulting disk completely covered. Early on next day a proton storm can be seen developing in the C2 FOV (also C3). The event is first seen in C3 at 23:18 UT above the NW Limb extending from the W up to past the N Pole. It is shown as a bright loop front surrounded by a fainter and diffuse envelope (shock?). By 23:42 UT, the C3 occulting disk is completely covered. By 01:42 UT (on next day), the LE on NW already crossed the outer edge of the C3 FOV. The mean plane-of-sky speed of the LE (outermost front of the diffuse envelope ahead of the loop-like feature) at PA 329 was ~2890 km/sec (as measured on C3 in only 2 frames, as it is two difficult to discern the feature tracked in the following frame, if not already out of the FOV). For the sake of completeness, the mean plane-of-sky speed of the LE of the loop-like feature at PA 329 was ~2400 km/sec (based on C3 data, only 3 frames). GOES reported an X2.6 X-ray flare during a long duration X-ray event on NOAA AR 10720 (N15W05) between 22:25 - 23:31 UT with peak emission at 23:02 UT (on 2005/01/15), most likely associated to the signatures observed on C2/C3. EIT 195 images show a strong brightening on the aforementioned AR starting at ~ 22:36 UT, peaking by 23:12 UT (there is a small EIT data gap between 22:36 UT - 23:12 UT due to the C3 Polarization sequence taken during that time). FC to NW of the AR is blown away during the gap. In summary, the event has therefore been determined as an asymmetric 'full' halo event, frontsided. Movies and images of the event will shortly be made available at: ftp://ares.nrl.navy.mil/pub/lasco/halo/20050115b Please note that by 2005/01/16 17:42 UT (C3 time) the proton storm still continues to be seen in the LASCO coronagraphs. Best wishes, Guillermo Stenborg +--------------------------------------------------+ Dr. Guillermo A. Stenborg 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 e-mail: stenborg@kreutz.nascom.nasa.gov +--------------------------------------------------+