Note on tracking Sun-Earth connection event

ICME Event: 2011/10/30

Observer: Eleni Nikou on 2019/06

1. ICME
  1.1. Catalog
     # Identified in ICME catalogs: Richardson & Can List
      RC catalog:
      Disturbance start time: 2011/10/30 10:01 UT
      Ejecta      Start time: 2011/10/31 01:00 UT
      Ejecta      End   time: 2011/10/31 15:00 UT
      dv = 30 km/s, v = 410 km/s, vmax= 420 km/s
      MC index:     0
      Dst:        -29 nT
      Suggested source CME: -
      V_transit: -
      
  1.2. Comments
      Overall ICME quality index: 3
      ICME signatures: Bmax: 13.2 nT
               ICME signatures: smooth v
      
      Disturbance time 410 km/s  -> search window 4 days -> 2011/10/26-27

2. CME
   2.1. A. Candidate A
    A.1. LASCO:    
      #CME 2011/10/26 at 10:00:05 UT, partial halo CME
           

    A.2. STEREO: 
           Data gap in COR2 from 07:24 UT to 13:24 UT.
	   If we combine the solar disc data with the C2 observations and timing it turns out that it is a front-side CME.

    A.3. AIA & GOES
	   corresponding flare: 26-Oct-2011 09:08 UT
           class: C1.2 at AR11324. 
           Not extended dimming area.

    A.4 Comment:  
	   Could be the source: The timing and orientation is in agreement with the observations


   2.1, B, Candidate B
     B.1. LASCO  
       #CME 2011/10/27 	12:00:06 UT, halo CME (from CDAW)
           

     B.2. STEREO
         front-side CME, first COR2-A image at 12:24 UT 

     B.3. AIA & GOES
          #GOES and Solar Monitor don't give a flare at that time. Looking at AIA observations in different wavelengths, we can see that there was a filament eruption at the nothern hemisphere. The orientation and the timing of the eruption and the halo CME match. We can't see dimmings at the location of the filament.

	
     B.3. Comment
          Could be the source: The timing and orientation is in agreement with the observations
  
   2.2. Comment


3. Other Comments

    The source of the ICME is not clear because both candidates could have caused it. Candidate A is slow and happened one day before candidate B, but candidate B is faster.
	
4. Summary
    SW index 3
    Source index 3
    Overall index 3