06:06 UT N West Very faint blob-like front starts to be visible at ~ 4.69 solar radii (PA ~ 315). An infalling structure can be seen by the time, a little bit to N. LASCO/EIT observed a complex 'full' Halo Event on 2005/02/01. Here is the report: 11:06 UT N East Very big and bright loop front. Close inspection shows that at least two different features are present: i) a ragged loop front developing toward NE (hereafter Feature #1), and ii) a wider loop front, a little behind, initially spanning from the N Pole up to the E Limb with its brightest part above E (hereafter Feature #2). By 11:30 UT, faint and diffuse extensions surround completely the C2 occulting disk. Feature #1 is first seen in C3 at 11:18 UT above the NE Limb, surrounded by a faint a diffuse envelope that, in the next frame at 11:42 UT, seems to extend all the way from the E Limb, N Pole, up to the NW Limb; it gradually subsides in the next frames. Feature #2 appears above the E Limb at 11:42 UT. By 12:42 UT, the C3 occulting disk appears completely surrounded by a rather circular front, which seems to be related to Feature #2 rather than to Feature #1. The mean plane-of-sky speed (based on C3 data) of different parts of the complex event is given below: - LE of the faint and diffuse envelope surrounding Feature #1 at PA 040 : 1300 km/sec (slightly decelerated), - LE of Feature #1 at PA 046 : 1046 km/sec (slightly decelerated), - LE of Feature #2 at PA 112 : 700 km/sec (too ragged the LE to have a precise measurement), and - LE of the circular front that surrounds the C3 occulting disk by 12:42 UT at PA 298 : 495 km/sec (too ragged the LE to have a precise measurement). No significant X-ray activity was reported by GOES by the time. EIT 195 running difference images show no significant activity on the disk. However, signatures of a backsided CME above the NE Limb starting at 10:36 UT can be clearly seen. In summary, the event has therefore been determined as a complex Full Halo event, most probably backsided. Please keep in mind that the global appearance of the event is given by the contribution of at least two different components (apparently both backsided). 12:06 UT S West During the development of one of the components of the halo event, a small system of loops develops along the streamer. All along the day, the whole structure is being shifted toward the S Pole. 17:54 UT E Limb In the halo aftermath, an elongated and ragged loop front that fades very close to the inner edge of C3. System of faint loops moving outward superposed in the LOS, until early on next day. 18:30 UT N East Expanding loop front. By ~ 20:58 UT, a ragged loop front develops moving faster, and thus disturbing the development of the previous loop front. Gusty outflow follows well into next day. Some infalling material on E Limb.
03:54 UT S Pole Continuous development of a system of diffuse and expanding loop fronts. 05:30 UT W Limb Spray-like front followed at 06:54 UT by a bright loop front developing slightly toward WNW. Only this loop front is discernible in C3. 10:30 UT NN East Diffuse and elongated loop front that fades throughout C2. Another one at 12:06 UT developing toward the N Pole.