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Double double...Gotcha!!

northernnutter

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Spica

Spica

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Hmmm... is this EPS LYR discussed I wonder? Been recommended a while ago, but I sorta dismissed it unwillingly, it just fell out.

I am up for the challange next clear night as well! I got hooked on doubles when observing ETA CAS a while ago, a truly wonderful sight of an orange dwarf surrounding a yellow very sunlike dwarf, separation a mere 13" if I recall right. What is yr estimate on the separation here, on the double double?

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Spica

Spica

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Should theoretically be resolvable with the 5" then! Gave it a go last night, rigged it all, but it instantly clouded over to the N-NNW. Instead there was a clear patch around the handle in big dipper, so I traded in for another well known double. Mizars very close companion was easily resolved at 43X, but not at 25X - seemed to be a bit of disturbances after all.

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John

John

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Should theoretically be resolvable with the 5" then!....

Yep - it's a relatively easy split with my 4" refractor if the seeing is anything like decent. Usually need 80x or so for a nice clean split.

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Spica

Spica

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Yep - it's a relatively easy split with my 4" refractor if the seeing is anything like decent. Usually need 80x or so for a nice clean split.

Great. Looking forward to this! I dislike using barlow though, perhaps my 9mm EP at 72X will do the trick, but it's not the best of an EP (Celestron Plössl, 3 elements I think, originally included in the Nexstar 130 GT package). Anyways, will give it a shot!

Tnx John

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  • 4 months later...
Donkeiller

Donkeiller

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Seeing was quite good last night- for a change!

Split the DD very easily in my 4" f/6 'frac with an 8MM BST giving me x77.

Tried using a 12mm BST- giving x51 and only just failed. Could argue it was split, but not 100% convinced.

Maybe with darker skies? - the sky was still quite bright/milky at 11.35pm

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  • 4 weeks later...
chiltonstar

chiltonstar

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Because of the very high contrast, my ED80 (Orion) splits the double-double very well at x60; optimum seems to be x150, which I suppose is the theoretical limit of the scope, although I have gone higher on eg Saturn. I use the ED80 as an indicator of seeing - if it's clearly split, I wind up the larger scope (5" Mak) and wait the necessary time for the optics to start to perform. I can see both pairs of stars at lower mag than x60 (ED80), but I wouldn't say they were "split" in the accepted sense - maybe the limitation is my eyes rather than the optics!

Chris

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Ibbo!

Ibbo!

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I had the 80mm Sw and Tak 60mm side by side a few years ago and we split it in both with a variety of eyepieces,not sure I could do it now at lower powers as the eyes are getting worse

might dig the baby Tak out and have a go

Steve

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lucjam

lucjam

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I'm waiting to have a go at this one with the 127.

I've only got the stock 25 and 10mm EP's though, will I struggle?

Looks like a semi clear night in London tonight so maybe... I guess I'll have my answer

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Stu

Stu

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The 10mm should give enough magnification but comments on here suggest that the quality of this ep is not the best.

As you say, only way to prove it is to try. Bear in mind that the seeing also needs to be reasonably good to split them so it's worth trying on a few clear nights (although I've forgotten what they are!)

Good luck

Stu

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  • 3 weeks later...
Qualia

Qualia

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I think the SGL "record" stands at x48......

Do you guys think I have split the same thing

Last night I went out on the roof, put my scope up high for the constellation Lyra and I split something with my 25mm workhorse (mag of 40x). I didn't think anything of it and decided that as a sketch it looked best at 18mm with the surrounding stars. I've drawn it up and will post what I saw in my blog. If it's not the Double Double in Lyra, then please let me know.

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John

John

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It's a great sketch but I'm not sure it's the "double double" Epsilon Lyrae. At powers less than 100x the stars would be very close together, almost touching and the two pairs lie at different angles to each other than the sketch shows. This shows the location of this set of binaries and an inset of what it looks like at around 100x, maybe a bit more:

post-118-0-17438500-1342294473_thumb.jpg

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Qualia

Qualia

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Okay, that's good. The sketch is definitely not Epsilon Lyrae, and I thank you John and Mark for politely pointing this out. Good on you, gentlemen.

Although I could be mistaken I'm certain I was in the constellation of Lyra and I spent a good half an hour or more trying to get what I saw as accurate as possible. The double was easily resolved in the 4" at around 40x to 50x and if you give or take just a millimetre or so, they came out with quite a healthy bit of spacing between them.

I've done a bit of hunting around and I think what I found was this: http://x.astrogeek.o.../log.php?o=1207 and http://bestdoubles.w...double-in-lyra/

The second site's is a lot more helpful and the photo seems to confirm my suspicion even more, both our west and north is indicating that pretty triangle system with the doubles setting the base and what is termed as the C component appears also to be highlighted in the sketch. Another double well worth checking out, and back to the drawing board for me to find Epsilon Lyrae.

Thanks for your kind words, TingTing.

P.S: I apologise for disrailing the thread, that wasn't my intention.

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  • 3 months later...
Donkeiller

Donkeiller

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Been progressively getting lower :smiley:

Can now "do" the DD at 61x fairly regularly.

Had one brilliant night, just over a week ago. Seeing was brilliant- I always take a peek at Polaris

at the start of a session and look at the stability of the diffraction rings at 188X.

Perfectly circular and rock-steady- makes a change :eek:

Got a split using my 12mm BST and Kson 102 f/6 at 51X.

First time I have been really convinced,

And the way the weather is looking- probably the last in a long time. :sad:

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