[BAA Comets] 174P outburst

[Nick James]

Thanks to Eric Watkins, Peter Carson and Denis Buczynski for submitting 
their images for measurement.

The latest plots are attached.

The total magnitude since the outburst has been remarkably stable at 
around 13.55 - 13.60 (unfiltered, UCAC-4 R mags). This is measured in an 
aperture slightly larger than the detected coma diameter.

The coma diameter continues to increase. Note that the two observations 
made by Denis shortly after the outburst were either very short 
exposures (Dec 9) or when the FWHM of the coma was only around 50% 
larger than the FWHM of the stars in the image. For these two 
observations the magnitude is reliable but the coma diameter probably is 
not.

If anyone has images taken prior to December 12 and has not yet 
submitted them please send the FITS files to ndj at nickdjames.com so that 
I can include them in the analysis.

Nick James


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