Note on tracking Sun-Earth connection event

ICME Event: 2011/09/09

Observer: Eleni Nikou on 2019/06

1. ICME
  1.1. Catalog
     # Identified in ICME catalogs: Richardson & Can List
      RC catalog:
      Disturbance start time: 2011/09/09 12:42 UT
      Ejecta      Start time: 2011/09/10 03:00 UT
      Ejecta      End   time: 2011/09/10 15:00 UT
      dv = 150 km/s, v = 470 km/s, vmax= 530 km/s
      MC index:     2
      Dst:        -75 nT
      Suggested source CME: 2011/09/06 23:05 UT
      V_transit:  680 km/s
      
  1.2. Comments
      Overall ICME quality index: 1
      ICME signatures: Bmax: 18.5 nT
               ICME signatures: u decreases a bit but smoothly, low beta, Tp<Texp, low n
      
      Disturbance time 470 km/s  -> search window 3 days -> 2011/09/06

2. CME
   2.1. A. Candidate A
    A.1. LASCO:    
      #CME 2011/09/06 02:36 UT, halo CME
           

    A.2 .STEREO: 
           Also seen as a CME in COR2-A and COR2 B (first frame at COR2-A 02:54 UT)
	   Front-side CME

    A.3. AIA & GOES   
	   corresponding flare: M5.3 at 2011/09/06 01:35 UT
	                        flare from AR11283 at N14W07

    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 2011/09/06 23:05 UT, halo CME 
           

     B.2. STEREO           
         Also seen as a CME in COR2-A and COR2 B (first frame at COR2-A 23:24 UT)
         front-side CME 

     B.3. AIA & GOES            
           corresponding flare: X2.1 at 2011/09/06 22:12 UT
	                        flare from AR11283 at N14W18

	
     B.3. Comment
          Could be the source: The timing and orientation is in agreement with the observations
  
   2.2. Comment
        We can observe extended dimmings for both candidates on the one side of the active region. Part of them is covered by the flare brightenings. 

3. Other Comments

     There is a partial halo CME on 2011/09/05 at 00:48 UT as seen from LASCO, but based on COR2 it is not earth directed.

     Both candidated have similar characteristics, but candidate A seems to be the source of the ICME. Based on the CDAW velocities candidate A is faster than A, and arrives on Earth faster. 

4. Summary
    SW index 1
    Source index 1
    Overall index 1