MLSO Mark-III K-Coronameter
Coronal Mass Ejection

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9 September 1997 . . . Day of year: 252

Direct ImageSubtraction Image
[Direct Image] [Subt. Image]
19:54 UT19:54 minus 19:20

Event Information

Event Description

This event began around 19:34UT. It contains a classic LOOP/CAVITY/CORE configuration, each of which were easily measured throughout the MK3 field of view and out through the LASCO C3 field of view. The above images show both the direct calibrated MK3 image taken from the K-Coronameter and the same image which has had a pre-event frame subtracted from it to extract more detail.
The outer loop is visible in both frames. In the subtraction image, the loop is a bright yellow. The leading edge of the cavity was defined for the purposes of these trajecotry measurements to be the trailing edge of the outer loop. This is usually indicated by a depleted region following the loop. The prominence material, or core, is usually visible as red in the subtractions and can be seen in the direct image above as a faint, white, dense region following the loop.

There is a MK3 direct-image movie [GIF, 664K] and a MK3 subtraction movie [GIF, 700K] to view for this event.

There is also a LASCO C2 movie [MPEG, 302 KB] and a LASCO C3 movie [MPEG, 238 KB] of this event as well.

Event Properties

There were a total of 51 data points obtained for use in trajectory fits. Of those, 16 were for the outer loop, 18 for the cavity, and 17 for the core feature.
The event times were from 19:34UT until 21:52UT . The event was visible in MK3 and continued past the LASCO C3 field of view. 

Central Position Angle:   ~307 - Loop	
   (in degrees)		  ~305 - Cavity 
			  ~303 - Core 	


Width (degrees): 	  ~45  - Loop   (MK3) 
			  ~23  - Cavity (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):	  19:23:31 - Loop    
			  19:30:30 - Cavity  
			  19:34:49 - Core    

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

Final Speeds (km/s):	     762.5 - Loop	
			     656.8 - Cavity 
			     579.6 - Core   
				

Accelerations (km/s^2):	      0.05  - Loop   
			      0.04  - Cavity 
			      0.008 - Core
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.

Trajectory Plots

(Click on plots to see full size)
First OrderSecond Order
(Loop, Cavity, & Core) (Loop, Cavity & Core)
[First Order Fit] [Second Order Fit]
MK3, C2 and C3MK3, C2 and C3

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, 664 KB]

MK3 images :

Best MK3 Subtraction Images

MK3 movie [GIF, 700 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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