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C/2014 E2 (Jacques) Returns

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132 replies to this topic

#126 canukLX90

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Posted 10 October 2014 - 11:43 AM

Welcome to the group. Thanks for your filter use observations and the update on the comet.

PJ

#127 Special Ed

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Posted 10 October 2014 - 03:13 PM

@ klyons--nice pic--thanks for posting.  Sure is a starry background.   :)

 

 

I'm new here, otherwise I would have replied sooner.  I viewed Jacques September 1 with my Z10.   It looked like a round nebula with a star in the center.  I did not see a tail.    The viewing was not good and it clouded up after about 20 minutes.   For jollies a tried a couple of filters on it.  The broadband LPR filter didn't do anything.   I tried an OIII filter because in the photos I've seen it had a greenish tint.   The OIII made it darker but I was still able to see it clearly.   It's hard to say if it added any extra details.  It was rapidly clouding up at this point.   So the comet had a OIII component otherwise the filter would have completely killed it.     I later saw that Lumicon has a Comet filter that passes the 501, 511 and 514 bands.  My OIlI passes 496 to 501.   So the OIII has other uses than nebulas.

 

pjsmith, welcome to CN.  You're smart to experiment with filters like that.  The Lumicon filter you mentioned is a Swan Band filter (they call it a comet filter) and passes the OIII line and the cyanogen lines.  It helps improve the contrast of comets with ionized gas tails but doesn't do much for comets that are mainly dusty.  So I guess that Jacques still has some gas to it even if you didn't see a tail.


Edited by Special Ed, 10 October 2014 - 03:22 PM.

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#128 Tonk

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Posted 03 November 2014 - 07:59 AM

... and the cyanogen lines.

 

Actually there are no spectral lines due to cyanogen in the green/blue region. The cyanogen "myth" has been around for at least 15 years now and just get repeated. Various websites (e.g. NASA, Lumicon) trot it out without a reference to the source (but also like to tell you that cyanogen is a deadly poison). There was a thread in this section of CN a couple of years back discussing the comet "cyanogen" spectrum issue - http://www.cloudynig...n/#entry5215844

 

Cyanogen radical fluorescence has a strong line on the UV/violet border. 

 

Green spectral lines from excited C2 radicals (carbon triple bond to carbon) is correct and these were originally discovered by William Swan in 1856 in the spectrum of butane flames.


Edited by Tonk, 03 November 2014 - 08:12 AM.


#129 Tonk

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Posted 06 February 2015 - 08:44 AM

I've only just got round to this - but my last session with Comet Jacques was the night 30th/31st August 2014 when I observed it on and off (using 8 x 50mm binns) over a 6 hour period passing very close to Mu Cephei - Herschel's Garnet Star.

I was also imaging the encounter and here is the first result (I'm also building a movie and 2D stereo but it takes time :lol: )

get.jpg
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#130 canukLX90

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Posted 06 February 2015 - 04:35 PM

Beautiful image Tonk.  You are the master in comet image processing.  Thanks for posting for all of us to enjoy!

 

PJ



#131 Rich (RLTYS)

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Posted 07 February 2015 - 07:39 AM

I've only just got round to this - but my last session with Comet Jacques was the night 30th/31st August 2014 when I observed it on and off (using 8 x 50mm binns) over a 6 hour period passing very close to Mu Cephei - Herschel's Garnet Star.

I was also imaging the encounter and here is the first result (I'm also building a movie and 2D stereo but it takes time :lol: )

get.jpg

That is an absolutely beautiful image.  :jawdrop:

 

Rich (RLTYS)



#132 djeber2

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Posted 07 February 2015 - 03:50 PM

great picture thanks for sharing



#133 Special Ed

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Posted 08 February 2015 - 01:47 PM

Yes, that is a really fine image--especially when you click to get the large version.

 

BTW, sorry to perpetuate the cyanogen myth in my previous post--I know that's a bee in your bonnet.  ;)   I should have known better since I've read what you've said about it in the past.




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