Revision as of 22:02, 18 April 2014

Comment Section

A good ICME, strong CME source, however, "stealth" surface signature (J. Zhang)
- A good example of "stealth" CME: bright CME, but no or very weak surface signature (in terms of no flare, dimming, filament eruption etc)
This event has a very difficult to distinguish source region, if you look very closely at S22 W38 just before 00:00 UT on the 10/05 it is possible to see a very small disturbance on the Sun, especially in 304 Angstroms. (Hess)
M. Temmer: clear on-disk signatures - movie from SDO - are visible. It is a "silent" CME, hard to catch for space weather forecasters, but not a "stealth" in sense of no solar surface signatures at all.

C. Moestl: looking at the whole October 4 SDO movie, there are also two other minor eruptions which I find very hard to distinguish from the 15 UT one (1. 7 UT, slightly west of disk center; 2. 0930 UT, south-east quadrant)
timing - evolution from SDO FoV to coronagraph - is an issue and needs to be looked at in detail
these eruptions are also visible in the SWAP data (http://proba2.oma.be/), including another minor one at 14h UT in the south-east quadrant (A. Devos)
Discussion in USTC-China ISEST Workshop on April 19, 2014
- Inferred from GCS model based on STEREO/A, STEREO/B and SOHO coronagraphs, longitude W11 deg, latitude S20 degree
- Around this position, there was a minor activity seen in SDO AIA images.
- In EUVI-A 195, there was a very faint eruption above the south-east limb. This beyond-limb faint eruption is consistent with the heliospheric position of W11S20.
- The CME continued to accelerate until 10 Rs with a peak speed about 800 km/s at 06 UT on Oct. 05.
- Consensus in the Hefei meeting is that this "stealth" CME originated from local corona, in contract to certain perception that "stealth" CMEs are from high corona. If the eruption started on 14 UT, and reach COR1 FOV at 23 UT, it means that the CME had a very-long slow-speed slow-acceleration phase.

A combination of SWEPAM and MAG data from the ACE Satellite:

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The blue lines are an approximation of the CME cloud and the red line denotes the shock.

Jmaps from STEREO A and B along the CME leading edge position angle

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 **Around this position, there was a minor activity seen in SDO AIA images.
 **In EUVI-A 195, there was a very faint eruption above the south-east limb. This beyond-limb faint eruption is consistent with the heliospheric position of W11S20.
+**The CME continued to accelerate until 10 Rs with a peak speed about 800 km/s at 06 UT on Oct. 05.
+**Consensus in the Hefei meeting is that this "stealth" CME originated from local corona, in contract to certain perception that "stealth" CMEs are from high corona. If the eruption started on 14 UT, and reach COR1 FOV at 23 UT, it means that the CME had a very-long slow-speed slow-acceleration phase.
 =Image Data=