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Friday, 8 November 2013

A Kinky Tail or Trail? Comet 2P/Encke

I had a good observing session again using the SON@OSC observatory. Again I have been using the beautiful 4" Pentax F4 refractor along with the SBIG ST8 camera.

How many of us make a "discovery" only to find that it has been known about for some time? There is though the satisfaction of knowing that you have spotted something out of the ordinary. :)

I have taken a number of images of 2P Encke that have shown it unusual tail, but one of this morning's images really brought it out. I posted it on the closed user group on Facebook "Comet Watch" this morning and it attracted quite a lot of positive comments and likes. Some of the comments also helped me to understand what is going on.

Before that, here is the image that I "played" around with to bring out the detail.



and a cutout section to show more



As you can see, especially in the second image the "tail" has quite a few kinks in it. My understanding - and please feel free to correct me if I am wrong - is that what we are looking at is the comet dust trail (not the tail) - the very same that causes the Taurids meteor showers. 

Why there are kinks is another matter. They have been known about for over a 100 years. This is a report from the MNRAS 1904.



It was to be more than ninety years after this visual viewing that trails were first imaged by large professional observatories and it was not until 2007 that amateur astronomers first imaged one. There is a nice article in Sky & Telescope about it 

A Comet Caught by Its Trail March 15, 2007 by Mike Holloway

Well worth a read, but to get back to the kinks,  Were they caused by comet outbursts, solar winds, coronal mass ejections or even close encounters with asteroids?  I do not know. I will continue to image the trail and to examine again some of my other images of 2P Encke. 

This morning I also imaged C/2012 S1 ISON, C/2012 X1 Linear and C/2013 R1 Lovejoy. These will be published shortly.

Comet 2P Encke is an interesting comet for a number of other reasons.

It was the 2nd Periodic Comet to be discovered (Halley is 1P/Halley)
It has a very short orbital time - just over 3 years - which means that there is a good probability that I will be able observe it a few more times at least :)

Thursday, 7 November 2013

Observing report for mornings of the 1st, 4th and 7th of November 2013

Observing report

The following images were all taken at the SON@OSC (Searchlight Observatory Network at the Observatorio Sierra Contraviesa)

4" Pentax Refractor at F4 plus an ST8 CCD camera

Observing 01/11/2013

Slightly overslept plus thin cloud to the East. Just suitable for C/2012 X1 Linear, and managed to capture C/2012 S1 ISON, C/2013 R1 Lovejoy and 2P Encke. In the case of 2P Encke I originally thought that the cloud was thick enough to hide most of the ion tail, however when I made a negative the ion tail is very clear, so much so that it has been complimented on Facebook Comet Groups.


C/2012 S1 ISON
C/2012 S1 ISON




C/2013 R1 Lovejoy
2P Encke

C/2012 X1 Linear - negative

C/2012 X1 Linear
























Observing 04/11/2013

This sky this morning was not very good as a mist came rolling in. This meant that imaging the two lower altitude comets 2P Encke and C/2012 X1 Linear was impossible. C/2012 S1 ISON when imaged was so faint it was useless. That left C/2013 R1 Lovejoy. The mist was thin enough to image this a number of times using the clear filter and also LRGB. On processing though it soon clear that the LRGB images were not very good and the once's through the clear filter although reasonable were not showing as much of the tail that other observers were seeing, though I have managed to bring out what I believe to be the ion tail in the negative.

C/2013 R1 Lovejoy

C/2013 Lovejoy negative showing tail


Observing 07/11/2013

Woke up at 4:30 ready to image the four comets. Disaster, the electric had been off the previous night and the CCD camera was warm. Set the cooling on, but there must be some slight condensation somewhere as it took just about the rest of the night to dry it out. :(  I managed to take a few images of C/2012 S1 ISON. I have trimmed the best one.

C/2012 S1 Linear


 This evening I intend to change the configuration!