Jie Format:
Note on tracking Sun-Earth connection event

ICME Event: 2009/12/19

Observer: Taylor Cox on 2018/11/27

1. ICME
  1.1. Catalog
     # Identified in ICME catalogs: Richardson & Cain List
      RC catalog
      Disturbance start time: 2009/12/19 10:00 UT
      Ejecta      Start time: 2009/12/19 13:00 UT
      Ejecta      End   time: 2009/12/20 17:00 UT
      dv = 20 km/s, v = 380 km/s, vmax= 430 km/s
      MC index:     0
      Dst:        -2
      Suggested source CME: 2009/12/16 04:30 UT H
      V_transit:  536 km/s

  1.2. Comments
      Overall ICME quality index: #
      ICME signatures: Bmax:  4.4 nT
                       Bz rotation
      Others ICME signature: 
      Peculiar behavior: density and temperature data is lost within the ejecta

      Disturbance time 536 km/s  -> search window 78 hrs -> 2009/12/16 04:00 UT

2. CME
   2.1.A.  Candidate A
    A.1. LASCO:
      #CME 2009/12/16 05:50 UT Full Halo CDAW
	   full halo can be seen emerging mostly from the top-left portion of the coronagraph at this time. Goes undetected by CDAW. 

     A.2. STEREO:
	    STEREO detects a CME emerging Earthward at 4:24 UT at the same day from both A and B. it is detected by both devices, and the strength, profile, and direction seem to all match up.

     A.3. AIA & GOES:
	    

     A.4. Comments:
             The nature of the full halo that is easily identified accompanied by clear STEREO confirmation make this a clear source for this ICME.

   2.1.B. Candidate B.
     B.1. LASCO:
      #CME 2009/12/16 19:00 UT CDAW
	A large CME off of the left disk could potentially be considered as a partial halo CME

     B.2. STEREO:
	   STEREO data on this day shows a full halo in STEREO B, and A suggests that it is in the Earthward direction. 

     B.3. AIA & GOES:
	    

     B.4. Comments:
             The halo detected on STEREO B makes this an unlikely candidate, but with STEREO B only about 45 degrees away from Earth at this point, and STEREO A confirming an Earthward direction, it isn't impossible that an edge of this expanding CME could affect the Earth.

   2.2 Decided Source
       The most likely solar source is Candidate A.

3. Other Comments



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