[Atmob-discuss] [AAVSO-DIS] Comet Holmes tonight (10/30), jet embedded in fan area

[Shawn Dvorak]

Mario Motta wrote:
> This is a link to image of Holmes with minor processing with curves, 
> shows a jet embedded in the fan area of the comet.
> 25 10 sec images stacked through the 32 inch telescope,
> Mario Motta
>
> http://www.atmob.org/gallery/showimage.php?id=719
>
> Mario E. Motta wrote:
>   
>> This gets any bigger, I am gonna need a bigger CCD chip! Measures about 
>> 14 arc minutes now. Still growing.
>> Taken at 11:30pm 11/30/07 with the 32 inch scope (4800mm focal length) 
>> and my SBIG STL 1001E camera. 25 10 sec exposures combined.  Link to image:
>>
>> http://www.atmob.org/gallery/showgallery.php?id=43
>>
>> Been said it looks like a planetary nebula. Tonight looking like a 
>> focault test mirror image, well undercorrected!
>>
>> Mario Motta
>>
>> _______________________________________________
>> Atmob-discuss mailing list
>> Atmob-discuss at atmob.org
>> http://lists.atmob.org/mailman/listinfo/atmob-discuss
>>
>>   
>>     
> _______________________________________________
>
> Aavso-discussion mailing list
> Aavso-discussion at mira.aavso.org
> http://mira.aavso.org/mailman/listinfo/aavso-discussion
>
>
>   
I finally got a somewhat clear night last night (it was looking like I 
was going to get shut out of the Comet Holmes fun) and saw much the same 
jet that Mario imaged.  This is a false-color composite of (31) 5-second 
unfiltered images with the 10" and SBIG ST-9: 
http://www.rollinghillsobs.org/images/P-Holmes.html.   North is at the 
top and east to the left and the field is 17' wide.   

The nucleus is the white area in the upper-right area at the center of 
the comet, while the "jet" trails off to the lower left.  Mario: what 
was the orientation on your image?   The jet in my image is orientated 
to the southwest of the nucleus, at approximately PA 135 degrees.  The 
comet is relatively symmetric radially, though there's a faint fan in 
the same direction as the jet (to the southwest).

Using a 12" aperture and an 80" annulus immediately surrounding the 
aperture I measured the nucleus' brightness at CCDR ~ 9.7, using r ~ 9.4 
for  the comparison star TYC 3334-0180-1 (mV=10.11, B-V=1.48).

Shawn Dvorak
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.atmob.org/pipermail/atmob-discuss/attachments/20071101/1cc5e204/attachment.html