Note on tracking Sun-Earth connection event

ICME Event: 2011/02/18

Observer: Eleni Nikou on 2019/05

1. ICME
  1.1. Catalog
     # Identified in ICME catalogs: Richardson & Can List
      RC catalog:
      Disturbance start time: 2011/02/18 01:30 UT
      Ejecta      Start time: 2011/02/18 19:00 UT
      Ejecta      End   time: 2011/02/20 08:00 UT
      dv = 130 km/s, v = 470 km/s, vmax= 600 km/s
      MC index:     1
      Dst:        -32 nT
      Suggested source CME: 2011/02/15 02:36 UT
      V_transit:  590 km/s
      
  1.2. Comments
      Overall ICME quality index: 2
      ICME signatures: Bmax: 13.2 nT
               ICME signatures: u decreases smoothly, low beta, Tp<Texp, low n
      
      Disturbance time 470 km/s  -> search window 3-4 days -> 2012/02/14-15

2. CME
   2.1. A. Candidate A
    A.1. LASCO:    
      #CME 2011/02/14 18:24 UT, halo CME, characterized as poor event by CDAW
           

    A.2 .STEREO: 
           Also seen as a CME in COR2-A and COR2 B (first frame at COR2-A 18:24 UT)
	   Front-side CME, consistent with the flare source region

    A.3. AIA & GOES
	   corresponding flare: M2.2 at 2011/02/14 17:26 UT
	                        flare from AR11158 at N56W18

    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 2012/02/15 02:24 UT, halo CME (from CDAW)
           

     B.2. STEREO
         front-side CME, consistent with the flare source region 

     B.3. AIA & GOES
          #GOES flare X2.2 at 2011/02/15 01:56 UT from AR11158 

	
     B.3. Comment
          Could be the source: The timing and orientation is in agreement with the observations
  
   2.2. Comment
        We can observe dimmings for both candidates, but we can't see them in full extend because of saturation caused by the flare brightenings. 

3. Other Comments

     Source: Candidate B, it is faster than candidate A and the timing matches better.

4. Summary
    SW index 2
    Source index 1
    Overall index 2