SOHO/LASCO Halo CME 20211009

Halo Alert: halo-message.20211009

UCMEO 93001 11009 1630/
11009 60742 91254 2971/ 296// 123// 40857
11009 60618 80658 10818 12882 1112/
99999

PLAIN

SOHO/LASCO HALO CME October 09, 2021

C2 Start Time:     07:12 UT

C3 Start Time:    07:42 - 12:54 UT (in progress)

Type of CME:
Asymmetric HALO CME — FRONTSIDE
pa1: 297      pa2: 296       Total Width: 360 degrees

Velocity Measurements:

C2    3 points    0716.5 km/sec @ PA 300
C3    9 points    0774.9 km/sec @ PA 297
Average through both fields:     0856.9 km/sec Acceleration: -33.18 m/sec^2.

COMMENT:      AIA 193 shows a flare of AR 12882 (long duration) at location [N18, E08]
                              06:18-06:58 UT. The event produces an EUV wave and a dimming
                                toward North and West, followed by a small post loop arcade.


            STEREO Beacon Data
            COR2 A, 07:23 - 09:38 UT; shows a CME from the West.
            Preliminary time/height measure gives 0967.6 km/sec @ 280 degrees.

NOAA/GOES reports a M1.6 class X-ray flare of AR12882 06:19/06:38/06:53 UT.

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/2021/211009/

Best Regards,

--Kevin Schenk

BT

[Images from the original alert message are omitted here]