MLSO Mark-III K-Coronameter
Coronal Mass Ejection

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23 October 1997 . . . Day of year: 296

Direct ImageSubtraction Image
[Direct Image] [Subt. Image]
20:29 UT20:29 minus 19:53

Event Information

Event Description

This relatively slow moving event allowed us to obtain quite a few datapoints for the trajectory estimate. While this event was visible in MK3 and LASCO C2 and C3 fields of view, there was some difficulty defining a loop structure with the C2 instrument and the C3 data for this time period wasn't clean enough to get reliable trajectory datapoints, so it was not used in the final estimate. The event became visible in MK3 at approximately 20:00 UT and measurements were taken through the C2 field of view until 23:47 UT. The cavity and core estimates are the most reliable because there was more confidence in those measurements.

There were a total of 110 datapoints for the trajectory fit. Of those, 17 were for the loop feature, 42 were for the cavity and 51 were for the core.

There is a MK3 direct-image movie [GIF, 1.209 MB] and a MK3 subtraction movie [GIF, 1.284 MB] to view for this event.

There is also a LASCO C2 movie [MPEG, 399 KB] and a LASCO C3 movie [MPEG, 726 KB] of this event as well.

Event Properties

There were a total of 110 datapoints for the trajectory fit. Of those, 17 were for the loop feature, 42 were for the cavity and 51 were for the core. The event times were from 20:00UT until 23:47UT . The event was visible in MK3 and continued past the LASCO C3 field of view. 

Central Position Angle:   ~80 - Loop	
   (in degrees)		  ~75 - Cavity 
			  ~90 - Core 	


Width (degrees): 	  ~51  - Loop   (MK3) 
			  ~32  - Cavity (MK3) 
			  ~ 3  - 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):	  20:06:57 - Loop    
			  19:20:35 - Cavity  
			  19:58:35 - Core    

Start Heights (Solar Radii):   1.7 - Loop  
			       1.2 - Cavity 
			       1.0 - Core  

Final Speeds (km/s):	     264.5 - Loop	
			     221.3 - Cavity 
			     199.5 - Core   
				

Accelerations (km/s^2):	      0.09  - Loop   
			      0.03  - Cavity 
			      0.02  - 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.

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, 1.209 MB]

MK3 images :

Best MK3 Subtraction Images

MK3 subtraction movie [GIF, 1.284 MB]

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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