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How difficult is epsilon lyrae?

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#1 emilslomi

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Posted 11 October 2021 - 05:26 AM

I'm a bit puzzled. Of course I have seen the double double plenty of times. It doesn't need a lot of magnification, and the splits are clear. I usually pay it a visit when I'm in the Lyra vicinity. I like it. I remember the first time a few years ago - the splits being aligned perpendicular to each other. But time and again, I see posts which somehow seem to suggest that the ability to see and split it is a special mark of quality of the scope (mostly refractors). I kind of got used to beginners proudly stating that they could clearly see the trapezium. That's me too not that long ago - so don't take it to be patronizing. But statements about the double double I also see from people who seem to have a bit of experience. Is it (supposed to be) difficult? or am I just lucky with my scope and eyes? Is there a freak chance that I have been looking at something much easier in close vicinity?

 

Emil


Edited by emilslomi, 11 October 2021 - 05:27 AM.

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#2 DLuders

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Posted 11 October 2021 - 05:32 AM

There are other factors to consider:

(1)  Seeing Conditions -- how turbulent are the skies?

(2)  Age of the astronomer's eyes.



#3 emilslomi

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Posted 11 October 2021 - 06:09 AM

There are other factors to consider:

(1)  Seeing Conditions -- how turbulent are the skies?

(2)  Age of the astronomer's eyes.

(1) I usually do not go out when the stars are blinking a lot. Unfortunately, I don't know how to rate my seeing. On the best nights, M35 is an averted vision bare eyes object, and the moon hardly ever starts boiling below 100x.

(2) 60+ but feeling quite good.

 

So, you think it may be considered difficult?

 

Emil



#4 Bean614

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Posted 11 October 2021 - 07:15 AM

".....posts which somehow seem to suggest that the ability to see and split it is a special mark of quality of the scope (mostly refractors)...."

 

I, too, find it quite amusing.  A recent post by a member in the Refractor Forum boasted of the optical quality of his 80mm APO.   He has been a CN member for 15 years, has Hundreds of Posts to various Fora, and was exceedingly pleased that his scope could split the Double-Double at 114X.   ?????????????????   

   I mean, Seriously?  Are folks really impressed by THAT kind of performance from an 80mm????

Even when living right next to the Boston Light-Dome (Before moving to my current Bortle-4 skies), smaller scopes, of toy-like quality, in terrible seeing, would split that at much less power!


Edited by Bean614, 11 October 2021 - 07:18 AM.

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#5 Voyager 3

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Posted 11 October 2021 - 07:37 AM

".....posts which somehow seem to suggest that the ability to see and split it is a special mark of quality of the scope (mostly refractors)...."

 

I, too, find it quite amusing.  A recent post by a member in the Refractor Forum boasted of the optical quality of his 80mm APO.   He has been a CN member for 15 years, has Hundreds of Posts to various Fora, and was exceedingly pleased that his scope could split the Double-Double at 114X.   ?????????????????   

   I mean, Seriously?  Are folks really impressed by THAT kind of performance from an 80mm????

Even when living right next to the Boston Light-Dome (Before moving to my current Bortle-4 skies), smaller scopes, of toy-like quality, in terrible seeing, would split that at much less power!

100s of posts doesn't mean he posted all those in double star forum . 

 

I guess it is that they are simply unaware of the fact that it is not "difficult" in a 80mm .



#6 Bean614

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Posted 11 October 2021 - 07:58 AM

100s of posts doesn't mean he posted all those in double star forum . 

 

I guess it is that they are simply unaware of the fact that it is not "difficult" in a 80mm .

"100s of posts doesn't mean he posted all those in double star forum"       I Agree!   I was just stating that to show that he is a "Seasoned" or "Experienced" observer.



#7 AdmiralAckbar

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Posted 11 October 2021 - 08:03 AM

I've wondered the same thing.

#8 emilslomi

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Posted 11 October 2021 - 08:05 AM

Let's take it easy. I'm not a double star geek and just looked at it initially because it is mentioned quite often. I plain didn't know if it should be considered difficult or not, although I couldn't fathom why it should be. That's why I asked. So, it's not. Good. Now that we are at it, I'd be happy if you suggest a difficult double for a 4 incher and an observer not usually spending a lot of time on doubles.

 

Emil


Edited by emilslomi, 11 October 2021 - 08:05 AM.

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#9 emilslomi

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Posted 11 October 2021 - 08:08 AM


I guess it is that they are simply unaware of the fact that it is not "difficult" in a 80mm .

I hope so too.

 

Emil


 



#10 rhetfield

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Posted 11 October 2021 - 08:11 AM

Splitting the double double is starting to get near the resolution limits of an 80mm scope.  It also needs sharp eyes and good EP's at lower magnification and good atmosphere at higher magnification.  There are times when my midwestern atmosphere makes it harder for me even though I have a bit bigger scope and the EP's to make it happen easily on a good night. 


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#11 Special Ed

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Posted 11 October 2021 - 08:16 AM

Emil,

 

Take a look at Phil Harrington's Cosmic Challenge for September:

 

A Trio of Binaries



#12 Mattimac

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Posted 11 October 2021 - 09:08 AM

Epsilon Lyrae is not difficult … just beautiful.  Physics in action!  

 

Always fun to show a group of young students who have never seen a double star before, let alone a double double system. First of course they see Epsilon 1 and 2 split widely, but you ask if they see anything unusual.  A few will say they appear oblong and one or two will see those split again into AB and CD pairs. “Like pearls on a fine necklace” one person said. Then those who missed it the first time crowd around to have a second look. Competition is a wondrous thing with kids. 

 

Then you ask how far apart they think the A and B or C and D pairs are?  When you tell them they are farther apart than the distance from our Sun to (minor planet) Pluto it blows them away.  You could literally drive our Solar System through the gap. They will be buzzing about what they saw for weeks. 


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#13 Jon Isaacs

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Posted 11 October 2021 - 09:27 AM

My two cents:

 

Many years ago on another forum, someone commented that the double-,double was a good measure of the seeing. As has been said, it's an relatively easy split in an 80 mm, I split it regularly in an ST-80..

 

When I see comments about splitting the double-double as a measure of optical quality in a 4 inch quality refractor, I strongly suspect that particular amateur is not an experienced double star observer...  Everyone knows the double-double, not everyone knows 32 Orionis (1.37"), Stelledoopie.it, the Rayleigh Criterion for 4 inch (1.36"), the Dawes Limit 10(1.14") for a 4 inch..

 

Jon


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#14 barbie

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Posted 11 October 2021 - 12:46 PM

The components of Epsilon Lyrae are very easily split in my 90mm f14 Maksutov.


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#15 Astrojensen

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Posted 11 October 2021 - 01:36 PM

For an experienced observer, the Double-Double is not difficult in a fine 50mm; for a very inexperienced one, perhaps in mediocre seeing, it can be a bit of a challenge in an 80mm. I think the reason it's so often mentioned as a challenge, is because it's mentioned as a challenge so often, that it's relatively well known... A bit of a catch-22. 

 

 

Clear skies!

Thomas, Denmark


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#16 flt158

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Posted 11 October 2021 - 03:27 PM

Back in the 1970s I had a 6" reflector. 

I also owned the book "All about Telescopes" by Sam Brown. 

He suggested I would have no hassle at all splitting Epsilon 1, 2 Lyrae at 100X. 

And of course he was right!

 

Since then I have split it at 112X with great monotony. 

My scope is now a William Optics 158mm apochromatic refractor. 

All 4 stars are white when I have them at the centre of the field of view (fov). 

 

Clear skies from Aubrey. 


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#17 barbie

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Posted 12 October 2021 - 12:56 PM

Same here Aubrey!!smile.gif


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#18 Bonco2

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Posted 12 October 2021 - 03:59 PM

I'm getting a chuckle out of this thread. Mainly because I too have wondered how often epsilon is referred to as a test of optics. Especially for telescopes  larger than 60mm. If one has difficulty viewing it with those scopes they either have really poor optics and/or poor seeing.  At any rate it's not a good indicator of telescope optical quality.  Personally I have no recollection of not being able to view clean splits it in 60mm refractors over MANY years. But I do find it a beautiful foursome and never tire viewing it. I think the lowest power was with my 60mm was around 100x.. Others may have done better.

It's a good discussion and a fine object for anyone wanting to observe binaries. My favorite difficult doubles for a small scope are Izar, Delta Cyg, Pi Aqil.  All doable in a quality 60mm but not easy and seeing needs to be rock solid. When I say doable I'm meaning being able to see duplicity, not necessarily a clean split.

Bill


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#19 John Fitzgerald

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Posted 13 October 2021 - 04:11 PM

Let's take it easy. I'm not a double star geek and just looked at it initially because it is mentioned quite often. I plain didn't know if it should be considered difficult or not, although I couldn't fathom why it should be. That's why I asked. So, it's not. Good. Now that we are at it, I'd be happy if you suggest a difficult double for a 4 incher and an observer not usually spending a lot of time on doubles.

 

Emil

Try Pi Aquilae m 6.3,6.8, sep 1.4" at PA 105 deg. If well split,

 

then,

 

Mu Cygni, m 4.8, 6.2, sep 1.5" at PA 323 degrees.

 

then,

 

Struve 2054 (in same low power field with Eta Draconis) m 6.2, 7.1, sep 1.0" at PA 350 degrees.


Edited by John Fitzgerald, 13 October 2021 - 04:19 PM.

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#20 emilslomi

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Posted 14 October 2021 - 02:11 AM

Just want to say THANK YOU for a couple of nice suggestions. If the skys permit, I will try some of them this weekend.

 

Emil


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