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Jupiter - but not as we know it


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Well after a good 3 hours observing, the first clear skies here for about a month, i finally got some good views of jupiter. I've been waiting for him to come around to my part of the sky and i wasn't disapointed. With my new shed working perfectly i bearly had to setup and at the end of my session it was a joy to just turn off my powertank, grab my laptop, lock the shed and go indoors. No more lugging 50kg of equipment back upstairs! Yay!

Well seeing as i finally got myself sorted equipment wide, i guessed i had better start making use of it. Jupiter was beautiful and i saw 4 moons in what appeared to be in a conjunction type arrangement all in a line with jupiter making the central jewel on a necklace or something. Pretty!

I took the time to stick my neximage ccd camera into the focuser, and took some shots. Tried with a barlow. Tried with 2 barlows. Couldn't seem to get any detail though. nothing like what i was seeing at the eyepiece. A shame as i was quite pleased with the views.

The attached image shows im ineptitude with imaging and my only defence is i dont do much at all (read this is about my second attempt all told)

I might blame the 2 dodgy barlows, but in reality it's just my lack of understanding and skill in adjusting the capture settings. Try try and try again i think is the solution!

This was taken with my ED100 at f36 (tal 2x 2" barlow, celestron omni 2x 1.25" barlow which i can blame the false colour on but not much else)

Comments welcome

post-12885-133877320296_thumb.jpg

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It was a stack of about 500 frames, i think the seeing was too bad for it to have any detail plus im happy to blame the poor quality of my barlows!

I tried to tidy it up a bit but i think i'll put this one down to experience and move on!

What planetary processing area?!

post-12885-133877320298_thumb.jpg

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I tried to have the gain as low as possible, the image was bearly visible on the screen before stacking. Apparently thats how it's done, but im no expert either. It's clearing up here, so im hoping for another night to have a bash at it. I may have a useable image before jupiter is out of season and im back at M42!

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Gordon, your image is focussed and isn't really burnt out except the odd patch which is difficult to avoid because jupiter has a big dynamic range. If you lower the gain too much you will end up with something resembling a Big Mac. It is difficult enough getting a decent Jupiter with good seeing at the moment and if the seeing is poor (it was horrendous here last night - the worst I have ever seen) then you have no chance. One thing you can do if the seeing is bad is do a manual selection of frames. This is best done using free software called virtual dub. Have a look in the Learning Zone at Planetary Imaging with a Toucam. However it looks to me as if you are on the right lines.

Experiment with a few different setting and Jupiter is definitely best on 5fps

So far I have really struggled to produce any sort of image.

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I'd guess because it's such a colourful object, with Venus and (to a lesser extent) Saturn you just get a one a coloured smugde to one side because the other colours arn't really very present for the scope to focus at different points. Jupiter is a much more varied object colour-wise.

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You'd still need the different colours to be present in the object in order for the refractor to bend them differently, Saturn is a pretty stange shape (to say the least) but doesn't show as much CA. :D

Surely the CA a object shows has got to be rooted in it's colour and brightness? :D

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Yes, but it is interesting that it is the red/blue spectrum that is effected...

I have found this:

(from an eyepiece primer)

The image seen while looking through an otherwise perfect telescope, while using an eyepiece that has noticeable lateral color, will in effect comprise different-colored images of slightly different sizes, superimposed. Most eyepieces with this problem have images whose size increases from the red to the blue end of the spectrum. With such an eyepiece, if the object you are looking at is a white circle, or something like it -- perhaps a planet or the Moon -- then when it is nicely centered in the field, the edge of the circle will look blue, where the large blue image overlaps beyond the edge of the smaller images of other colors. If you are looking at a test pattern of black and white stripes, then the sides of the white stripes that are away from the center of the field will have blue edges, and the sides toward the center of the field will have red edges.

The width of the red and blue edges will increase in proportion to the distance of the edge from the center of the field. Lateral color, from the eyepiece, goes away when an small object is centered. Longitudinal color, from the objective, does not.

Interesting...

I still think the answer is in part connected with Jupiters 'fat in the middle' shape.

I've got a bee firmly in my bonnet now!

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The lower down Jupiter is the more you get, so maybe thats a part of it. I don't remember it happening with my Newt/Mak though, just refractors, which would indicate(?) its a scope/atmospheric affect rather than just atmospheric? :D

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It might be partly a refractor thing (Anyone have a pic of Jupiter taken thru a Newtonian?).

I am starting to think that it has more to do with the behaviour of red/blue light and its ability to travel thru atmosphere than the scopes optics?

That and Jupiter's odd shape (its size and gaseous nature causes it to swell around its middle as it spins). The colour fringing appears strongest around its middle - there must be a connection.

Intriguing :read2:

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Heres one with my Intes Mak back in April, some colour but not much.

Still the characteristic red one side/blue the other.

I'll buy that the atmosphere has an effect, I remain to be convinced the shape does.... :sunny: :D

I'll redouuble my efforts to find a link :D :D :lol:

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Interesting stuff..

I always thought it was due to the atmosphere refracting the light

and splitting it into colour similar to what a prism does.

The spectrum from a prism is red one side and blue the other.

Looked at some shots I took last year when Jupiter was higher

and with the same gear, the colour shift was much less then.

Mind you, I am of a certain age when most of what I say shouldn't

be trusted :D

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I'll redouuble my efforts to find a link :D:lol: :lol:

OK, I give up!

It is an atmospheric effect as described above - the red appears near the horizon and violet toward the zenith - that it is consistent with Jupiters shape is just a coincidence.

Gaz wins!!!!!

:D :D

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So we have learnt that the atmosphere messes with the colours and puts them out of register. Presumably, as the spectrum is continuous, the only way would be to LRGB the beast with narrow bandpass filters then combine in Photoshop? In that case, what would you choose for the luminance channel filter? I'm wondering if there would be any Ha light reflected (as that's the only bandpass filter that I have) to get rid of the atmospheric smearing.

Captain Chaos

Edit

After researching it I discoved that the solar continuum filter that I have is actually a bandpass filter. So where does the "continuum" bit come from? I'll try for a Mono CCD version to see if it comes out in focus.

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