MLSO Mark-III K-Coronameter
Coronal Mass Ejection

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1 December 1997 . . . Day of year: 335

Direct ImageSubtraction Image
[Direct Image] [Subt. Image]
18:37 UT18:37 minus 18:22

Event Information

Event Description

The MK3 data for this day is limited with only a few images available. There were enough images, however to obtain trajectory fits. This event shows a bright LOOP/CAVITY/CORE structure with details easily seen in the MK3 subtractions. By the time the event had approached the end of the MK3 field of view, this structure had distorted into what was called the 'radial spike' mentioned in the LASCO notes. As the event moved into the C2 field of view, the tip of this spike was measured as the frontal loop feature and this continued out through the C3 field of view because this was the only distinguishing feature in those instruments.

There is a MK3 direct-image movie [GIF, 207K] and a MK3 subtraction movie [GIF, 228K] to view for this event.

There is also a LASCO C2 movie [MPEG, 87 KB] and a LASCO C3 movie [MPEG, 154 KB] of this event as well.

Event Properties

There were a total of 26 data points obtained for use in trajectory fits. Of those, 17 were for the outer loop, 4 for the cavity, and 5 for the core feature. The LASCO C2 and C3 measurements were of the frontal loop feature only. There was not enough detail to identify cavity or core features in those instruments.
The event times were from 18:32UT until 19:33UT . The event was visible in MK3 and continued past the LASCO C3 field of view. 

Central Position Angle:   ~71 - Loop	
   (in degrees)		  ~57 - Cavity 
			  ~59 - Core 	


Width (degrees): 	  ~28  - Loop   (MK3) 
			  ~13  - Cavity (MK3) 
			  ~ 5  - Core   (MK3)
The following data is obtained from performing a second order, least squares fit of the trajectory data points (Hundhausen, et al, 1994) : 
Start Times (UT):	  17:59:49 - Loop    
			  17:54:59 - Cavity  
			  17:05:57 - Core    

Start Heights (Solar Radii):   1.0 - Loop  
			       1.0 - Cavity  
			       1.2 - Core   

Final Speeds (km/s):	     284.9 - Loop   
			      91.9 - Cavity  (end of MK3)
			      91.1 - Core    (end of MK3)
				

Accelerations (km/s^2):	      0.003 - Loop   
			     -0.02  - Cavity  (only 4 datapts)
			      0.01  - Core    (only 5 datapts)
The above numbers were produced from a second-order fit of trajectory data which began in MK3 and ended in LASCO C3. Estimated start times, start heights, final speeds and accelerations are available in each individual data set (MK3, C2, and C3) where enough data points were available. That information is not presented here. Final speeds were evaluated at last data point in C3, unless indicated otherwise.

Image Gallery

A gallery of the `best' direct and the `best' subtraction images (`display' version) from this event may be accessed below.

Be aware that these are only a few of the images that you may access. For a complete list of images, including the `computational' versions, please visit our FTP site.

All times are given in Universal Time (UT) units.

Best MK3 Direct Images

MK3 movie [GIF, 207 KB]

MK3 images :

Best MK3 Subtraction Images

MK3 subtraction movie [GIF, 228 KB]

MK3 images :

References 

Hundhausen, A.J., J.T. Burkepile, and O.C. St.Cyr,
  Speeds of coronal mass ejections:  SMM Observations
  from 1980 and 1984-1989,
  J. Geophys. Res., 99, 6543-6552, 1994.

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