UCMEO 93001 31211 2200/ 31208 61612 82030 0002/ 360// 213// 30706 31208 ///// ///// ///// ///// ///// 99999 PLAIN SOHO/LASCO HALO CME December 8, 2023 C2 Start Time: 16:12 - 16:24 UT C3 Start Time: 16:42 - 16:54 UT Type of CME: Asymmetric HALO CME — BACKSIDE pa1: 000 pa2: 360 Total Width: 360 degrees Velocity Measurements: C2: 7 points 741.3 km/sec @ PA 311.43 C3: 10 points 689.3 km/sec @ PA 311.38 Average through both(C2/C3) fields: 706.0 km/sec Acceleration: -25.59 m/sec^2 COMMENT: LASCO C2/C3 show a very faint asymmetric halo CME. The CME emerges with a bright core in the NW. The halo CMEs source is a far-sided eruption, evidence of faint field line movement visible beyond the NW limb at 16:10 UT as best seen in SDO AIA 171. STEREO Beacon Data COR2 A, shows a asymetric halo emerging from all directions with faint lines in the west and very faint lines in the east, starting between 16:23 - 13653UT. Preliminary time/height measurements gives a velocity of 581.6 km/sec @ PA 276.52 using 6 points of measurement. Preliminary UCMEO velocity and position measurements are delivered first. Images, movies, and time/height information for this event will be available at: https://umbra.nascom.nasa.gov/lasco/observations/halo/2023/231208 Best Regards, --James Tabourne BT [Images from original message are omitted here] ________________________________________________ Soho-halo-alert mailing list Soho-halo-alert@mail.nascom.nasa.gov https://mail.nascom.nasa.gov/mailman/listinfo/soho-halo-alert