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Old 12-01-2012, 08:39 PM
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Hi Ian, good report and especially interesting that you could still see the comet with naked eye averted vision. Unfortunately cloudy here for tonight.

All the best.
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  #502  
Old 12-01-2012, 09:02 PM
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Here is the same image inverted, and shows the length of tail better.

http://i638.photobucket.com/albums/u...s/144c4e29.jpg
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  #503  
Old 12-01-2012, 11:04 PM
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Quote:
Originally Posted by Ian Cooper View Post

It was a hard case situation with the solar twilight receeding in the west and the lunar twilight growing in the north east. In between and up high in the south sat the Clouds of Magellan in the darkest part of the sky. A very vague but persistent appendage to the LMC coming off underneath the Tarantula end of the Bar was best seen with averted vision, but occasionally with direct viewing. A few pesky clouds tried forming in the area. They moved off but the weak, elongated glow persisted. Binoculars weren't any help at all.

I'd say that the tail was no more than 8 degrees long, about the same as the brighter part shown in Lester's picture. In positive and negative views of Lester's shot there is a weak suggestion that the comet may trail off beyond the LMC, but it is not certain.

When I looked to my north I saw lightning flashes so it was good of them to hold off for an hour, otherwise I doubt that I will get another chance before Monday night. I just splashed out on a 450D so the weather will be puke for me for the next few days. Then I'll be ready to give it another crack!

Cheers

Coops
Excellent Ian! Can confirm - to me the comet was naked eye in averted vision before moonlight killed it. I could see it as a faint bar of light extending as far as the Tarantula Neb end of the LMC.

Not much time tonight and I was fiddling with camera & mount for all of the best viewing and shooting time (mucking about with the alignment, getting the right field etc) so I didn't devote much time to visual, not expecting to see anything anyway. By the time I got everything going the Moon had risen and the subs were pretty washed out. Negative shows it best, confirms my visual sighting as far as position goes:
http://i727.photobucket.com/albums/w...2012invert.jpg

Tomorrow should be better if the clouds hold off. Next few nights have potential for great images, as the tail passes over the LMC.

Cheers -
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Old 13-01-2012, 07:39 AM
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Fabulous news there Ian!! I had thought it was well and truly done visuall, you must have good eyes though.

Excellent image there Rob, love it!!
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Old 13-01-2012, 11:10 PM
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Hi all, at last clear dark skies. This is a 2 minute exposure with 50mm lens at F2, and Astro 40D at ISO 800. Looks like the tail goes well past the LMC. I could not see the comet naked eye, and the sky was very clear, as I could count easily 30 stars within Orion.

http://i638.photobucket.com/albums/u...s/844abef5.jpg

Inverted view.

http://i638.photobucket.com/albums/u...s/a580d233.jpg
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  #506  
Old 13-01-2012, 11:51 PM
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Great image Lester. Is it me or does Lovejoys tail extend past the Large Magellanic Cloud in the inverted view? Inverted images seem to reveal more detail then images that are not inverted.

Sean
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Old 13-01-2012, 11:53 PM
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Thanks Sean, yes there is a very faint hint of the tail going past the LMC.

Here is a stack of 18 x 2 minute exposures, inverted that shows the tail slightly better.

http://i638.photobucket.com/albums/u...s/3f8c5e14.jpg

Last edited by Lester; 14-01-2012 at 08:03 AM.
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  #508  
Old 14-01-2012, 08:17 AM
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Well done Lester, another great image, but as Sean points out ... look at that tail!!

I skimmed over the 1st images, but went back after Seans comment = wow!! Your new image shows it well, I wonder how many degrees the tail is now, as it looks looooong.
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  #509  
Old 14-01-2012, 08:55 AM
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Lovely shot Lester, it sure shows what a difference a darker sky and
no moon makes.
Here is my full frame set with the QHY-8 and 80-200mm SLR lens from
this morning.
Moon was well up, suburban Adelaide.

Maybe just a hint of tail when I stretch the full frame.

Steve
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Old 14-01-2012, 09:27 AM
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Thanks Liz and Steve for your comments. I will have to put the head of the comet closer to the edge of the frame next time, or even go back to the 24mm lens. Rob has measured the tail to extend for over 22 degrees on his image from last night.

Steve, I don't know if there is a filter that would help in your situation. I did pop the question on another thread a few weeks ago, but without any real answers.

All the best.
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Old 14-01-2012, 09:55 AM
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Not the greatest conditions here last night - clear but transparency was a bit off. Nothing naked-eye really, but did get an image. Squeezed a bit it shows faint trace of the tail out to 21-22 degrees with the last little bit out to the edge of the frame lost in vignetting (quite possible) or not there. Anyway, still over 20 degrees long.
http://i727.photobucket.com/albums/w...ullinvredb.jpg

Here's my 'pretty pic' shot (crop) - not so pretty, eek....
http://i727.photobucket.com/albums/w...UT55mmcrop.jpg

Like Lester, I will shoot wider tonight if conditions allow. His shots are superb!

Cheers -
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Old 14-01-2012, 09:58 AM
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Wow Rob, great shots, the tail on the negative is so impressive.
Great documentation of the last weeks of this sungrazer guys!

Steve
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Old 14-01-2012, 11:34 PM
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Thanks Steve. I shot wider tonight (18mm), and I think you can safely say the tail is at least 37 degrees long, possibly out to 45-46 degrees, and if it persisted after that it's lost in the bright Milky Way starfield. Tonight the tail was going right over Canopus. Visually I couldn't see anything of the tail.
http://i727.photobucket.com/albums/w...taillength.jpg

At 55mm the tail extends faintly out of the bottom-left corner of my frame, a length of 20 degrees:
http://i727.photobucket.com/albums/w...length55mm.jpg

My gear isn't really suited to this stuff - a basic, old entry-level DSLR with cheap lenses, on a rickety unmotorised EQ1 mount and 'guiding' through a reticle with the slo-mo knob. It would be great if someone could repeat this with a halfway decent imaging rig - waiting on Lester, hopefully he's done the business again!

Cheers -
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Old 15-01-2012, 08:06 AM
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Hi all,

Shot the comet last night in windy conditions with cloud causing lots of frames to being useless. This was taken with 24mm lens at F2, and Astro 40D at ISO 400 with 8 minute exposure. I wanted to try some 12 minute exposures, but cloud arrived. I should have had the comet further to the right in the FOV, as the tail extends out of the frame being over 36 degrees in length. I notice a fork tail in the thumbnail with one extention going above Canopus.

I have just taken flat frames for the first time, with a piece of white cotton material over the end of the lens, pointed at the sky. Using the same F ratio,focus and ISO as last night images. Standard exposure with histogram central, took 10 frames and added them into the mix for DSS. The result seemed to reduce the vignetting very well.

http://i638.photobucket.com/albums/u...s/dc10a80c.jpg

Last edited by Lester; 15-01-2012 at 11:10 AM.
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Old 15-01-2012, 08:24 AM
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Fabulous shots again guys!! Look at that tail piercing Canopus and LMC, amazingly long and well measured for us Rob.
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Old 15-01-2012, 10:57 AM
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Doing well there Rob and Lester. I tried last night but too much scattered light and cloud to image the tail. It is just so faint now.

btw I've downloaded the fits files from hubble made on January 7, but alas nothing clearly visible. But boy they are noisy with all the cosmic ray strikes and the field of view is only 3' so I'm not sure if the were on target or not. Maybe with further processing something might show up. Congrats to Matthew Knight from Lowell observatory for getting time on the hubble!

Terry
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  #517  
Old 16-01-2012, 12:26 AM
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Thanks Liz and Terry.

Here is tonights image, 15-1-12. 5 x 12 minute exposures at ISO 400 with 24mm lens at F2. If the tail reaches the edge of the frame it would be just over 47 degrees long. I am not sure if it goes that far, but Rob will process it a bit more and see how far it goes.

http://i638.photobucket.com/albums/u...s/47a04e12.jpg
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  #518  
Old 16-01-2012, 01:24 AM
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My 30 sec x 100fr set from tonite, 15th Jan
60 sec x 50 frame set still to process

Steve
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  #519  
Old 16-01-2012, 05:28 AM
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The very faint tail in Lester's image is about 22 degrees long, the "brightest" part is about 5 degrees.
The greenish Vela SN remnant is visible on the lower left side of the image.
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  #520  
Old 16-01-2012, 05:35 AM
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Great images Lester and Steve.

yes, that tail zooms right past Canopus Lester.

Interesting re Vela SN remnant Glen.
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