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DOUBLE DOUBLE - Wow!


Coco

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Last night I had a brief observing session in cloudy Lancashire, managed to hide myself in my obs with just the front OTA pocking out of the roof, Ive made a blind arrangemnt on my obs (pent shed) so I can keep out 90+ outside light.

Firstly I cant believe how much M13 looks when observing with near total darkness around, whilst the sky wasn't 'black' the obs darkened made a massive difference.. worth the effort.

M13 through the Megrez 110 & Skywatcher 9mm LER barlowed up with a Celestron Ultima 2x looks fab, no centre stars but many outside made interesting viewing, next a target Ive been meaning to observe and that was the Double Double in Lyra ,, Just split but quite a lot of false colour through cheap eyepieces and f/5.95 scope, But they were there! :)

Short session but fab night!

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You know you have a real good scope, when you can split each pair of the stars, and still see BOTH sets in the eyepiece at the same time! That takes a combination of real FOV AND high definition ! The close pairs are split at about 90 degrees orientation from each of the wide spaced pair . ( hope I am explaining it well enough )

Jim S.

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You know you have a real good scope, when you can split each pair of the stars, and still see BOTH sets in the eyepiece at the same time!

That would explain why I failed at this last night... Thought I'd be able to do that. Just looked on a whim though - didn't know what to expect really.

Tom

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whilst the sky wasn't 'black' the obs darkened made a massive difference..

Nils Olof Carlin (inventor of the Barlowed Laser Collimation technique) reckons that truly dark-adapted eyesight is impossible even under the darkest sky: "I believe the increased light sensitivity with averted vision possible at high powers is a function of better dark adaptation, and thus takes time. The best dark country sky (22 MSA according to Brian Skiff, 24 MSA according to Clark) is too bright to allow full adaptation"

- which suggests a darkened Obs is indeed the best way.

(or of course, a big, black sheet to hide under! :) )

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They are a good test of the current conditions when observing and our equipment, I had a look at them recently when out looking at a few double's, although split at 261x the image presented was not that great but it was still incredible all the same.

Nothing beats a dark location to observe from. looks like you have a good option there.

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Oh, I should mention that "seeing" should be pretty good, too! If your star images are bloated, and/or moving around, you are really going to have trouble splitting the individual pairs! A good indication of good "seeing" is a lack of "twinkling" to the naked eye !

"Twinkle Twinkle little star" may be a nice children's poem, but it is one of the worst things one wants to see when attempting to split doubles !

Jim S.

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Nice one Guy.

I really like the Epsilon Lyrae. I must confess that this is always an easy split in my 6" f11 dob. I can track at 300-400x (EQP) and get nice sets of Airy rings on both (all four stars) with my 6-3mm Nagler zoom at 4mm. Not looked at it for a few weeks but will be doing next time it's not cloudy or windy!

In my 12" f5 dob this was always more challenging but generally split. Focal ratio seems to make a big difference in some of the doubles, perhaps due to smaller exit pupils making the split more clean?

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Hi

On a good night I have split both in the double double in the same FOV with my Skymax 102 and Seben Zoom EP at 8mm (x162). Nice airy discs around all 4 stars - stunning!

Scope had plenty of time to cool - very important with a Mak.

Seben have a bad name in the astronomy world but I find this cheap zoom eye piece very useful with my high FL scope - I wonder what difference a Baader zoom at x4 the price would be like?

Clear skies

Paul

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I posted a previous thread where, under pretty average conditions here in belgium, I could split the double double at x48 !!

Using a 25 yo 4" Genesis and a 10.4 TV plossl.

You need to take your time and concentate.

Once you have split them, try again with a slightly lower magnification - you may be surprised how low you can go!

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Was viewing this the other night with the 4" apo and alternating between 7t6 nagler and 3 to 6 tv zoom.

The apo gives really nice tight star images and it was a nice easy split. Could see both pairs in the same fov even at 4mm. It does seem to be easier in frac's or smaller scopes which are less sensitive to seeing.

It's one of my favourites :-), along with m13

Cheers

Stu

Sent from my GT-I9000 using Tapatalk

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