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June's AN Double Star of the month - Struve 1964


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As the seeing last night was so good (Carpe Diem), I had a look at AN's double star of the month for June, Struve 1964 in Corona Borealis. With my 180 Mak at x190 and x270, it appears as a very pretty triple, a bit like Alkalurops nearby, but quite faint with white/blue-white stars. In CDSA it is said to be a "tiny visual quadruple", but I could only see three stars  (A, C & D) - in AN the author was also unable to resolve the AB pair.

Anyone had any luck with this as a quadruple?

Nearby Zeta CrB, Delta Boo, Alkalurops and of course Izar were also glorious - the Vixen SLV 15mm is excellent for doubles!

Chris

 

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On 7/6/2017 at 10:16, paulastro said:

A lovely description Chris.  It's inspiring me to take a look myself, when the weather permits.

 

I've had a second look, and this time split the second pair - it is a superb grouping like a miniature double-double. In fact, when I googled it (this time using the correct Struve number!) it is listed as such on other forums (or fora, depending on preference). Wel, worth a look, but faint.

Chris

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On 07/07/2017 at 15:11, chiltonstar said:

I've had a second look, and this time split the second pair - it is a superb grouping like a miniature double-double. In fact, when I googled it (this time using the correct Struve number!) it is listed as such on other forums (or fora, depending on preference). Wel, worth a look, but faint.

Chris

I thought I'd try my hand at finding Struve 1964 last night. The day had been promising but as the sky grew dark the clouds began to move in. There were still some sucker holes that enabled me to follow a thread of doubles in Bootes leading to 1964, at least im assuming my final destination was 1964. The sky was not clear, as thin cloud plagued the view even in the apparently clear bits, and with the sky not being truly dark it was at times a bit of a challenge.

If the binary was indeed Struve 1964 I was unable to detect any fourth component. Perhaps on a more transparent night I will give it another go.

 

2017-07-09 10.10.25.jpg

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Very accurate sketches Mike: my first view of Struve 1964 looked exactly like your sketch, but second time round with less LP from the Moon and less haze, I spotted the faint secondary alongside the primary star. Might be a little difficult with less aperture though as it's only mag 9.9....

Chris

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12 hours ago, chiltonstar said:

Very accurate sketches Mike: my first view of Struve 1964 looked exactly like your sketch, but second time round with less LP from the Moon and less haze, I spotted the faint secondary alongside the primary star. Might be a little difficult with less aperture though as it's only mag 9.9....

Chris

Hi Chris,

Well, last night was much clearer than the night before and seeing and transparency was quite good. So, here's my interpretation of Struve 1964 from the evening of 9/7/17. I believe I saw all four components after spending quite some time letting the binary drift repeatedly across the field of view. I've been wrong before and I'll be wrong again, but looking at the attached sketch, how does the positioning compare with what you saw? This was difficult and increasing the power didn't really help much, but after repeated passes I convinced myself of the tiny stars existence. At 9.9 it would have been easy had it been a stand alone star, but close up against its brighter primary its a pig! 

 

2017-07-10 09.15.34.jpg

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'Bout right I think. I saw it as pointing in the direction of the other pair, about due E. Well done - 100mm can certainly deliver (I love my 102mm Vixen lf achromat, but it doesn't get out as often as it should...)

Chris

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Just caught up with this thread. Great reports and a compelling target for my next clear night :icon_biggrin:

I wish I had a mount that could handle 3 fracs - it would be fun to set up the Tak 100, ED120 and TMB / LZOS 130 in a line and move from scope to scope on a challenging binary like this :icon_biggrin:

 

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Really liked this thread. Checked my records and have not seen Struve 1964 so must give it a go. Great write ups and some excellent drawings by Mike. I notice that this double star appears in the 'Visual Atlas of Double Stars' produced by the Webb Society together with a drawing.

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Well the clouds are making things awkward but I got the 3 stars of Struve 1964 nicely with the ED120 at 225x and 257x. I was getting into the "groove" and I think I saw hints of the faint mag 9.9 star very close in to the brighter A star but a thin (and unwelcome) cloud layer has just arrived and prevented extended study this evening. Have to wait for another night but at least I know where to find this one now !

Struve 1965 close by is a lovely pairing so I got distracted by that for a few minutes.

Saturn putting up a great show as well with the C-ring on view quite clearly at times.

As is often the way, I'm thinking that it could be an excellent viewing night ....... if it wasn't for the clouds :rolleyes2:

 

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10 hours ago, John said:

Well the clouds are making things awkward but I got the 3 stars of Struve 1964 nicely with the ED120 at 225x and 257x. I was getting into the "groove" and I think I saw hints of the faint mag 9.9 star very close in to the brighter A star but a thin (and unwelcome) cloud layer has just arrived and prevented extended study this evening. Have to wait for another night but at least I know where to find this one now !

Struve 1965 close by is a lovely pairing so I got distracted by that for a few minutes.

Saturn putting up a great show as well with the C-ring on view quite clearly at times.

As is often the way, I'm thinking that it could be an excellent viewing night ....... if it wasn't for the clouds :rolleyes2:

 

Despite all our (understandable, well we're British) moans about the weather and ok, it has been cloudy quite a bit, nevertheless the seeing recently has been spectacular! As well as the views of difficult doubles like Struve 1964, I agree that sometimes Saturn has been very impressive considering the altitude (and the odd difficulties like sheep and roofs getting in the way of the line of sight) with plenty of detail both visually and imaged.

Struve 1965 is nice, isn't it?

Chris

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I've just been playing with my wife's gel pens in an attempt to draw stars on black paper. I'm not sure what to think! Star colour should be taken with a pinch of salt as they are merely my own interpretation and not necessarily accurate. In fact the colours depicted may be nothing like the reality. 

Attached are colour versions of the stepping stones I used to get to Struve 1964. It was a pretty journey! ?

2017-07-11 15.01.38.jpg

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6 hours ago, chiltonstar said:

Despite all our (understandable, well we're British) moans about the weather and ok, it has been cloudy quite a bit, nevertheless the seeing recently has been spectacular! As well as the views of difficult doubles like Struve 1964, I agree that sometimes Saturn has been very impressive considering the altitude (and the odd difficulties like sheep and roofs getting in the way of the line of sight) with plenty of detail both visually and imaged.

Struve 1965 is nice, isn't it?

Chris

I've not had sheep in the line of sight problems here, as yet. I've had cats though - they walk along the roof ridges and have occasionally "occulted" a target while I've been observing it. That causes plenty of puzzlement until I realise whats happened :rolleyes2:

 

 

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I've just spent an hour and a half observing this double double. Getting to Struve 1964 was quite straight forward using Alkalurops and Zeta CrB as markers and the two close stars HIP 75928 and HIP 76006 as confirmation that I was looking at the correct location. On first observation it occurred to me that I had the wrong star as I could only see a double star and then I thought, no I must be in the right place but my telescope/conditions weren't good enough to split the smaller stars. My previous smallest split has been Izar with a separation of 2.89" and I can barely see dark space between the two stars. If you are struggling to split the Struve 1964 doubles then the other doubles in the area, Mu 2 Boo (Alkalurops double) at 2.25" separation and Zeta CrB at 6.36" separation are great to view and achieve a good focus. On checking the separation of the Struve 1964 doubles it's no wonder that they are difficult to split with AB separation at 1.34" and CD at 1.44".

I came back in from my garden to read this thread again after failing to split AB and CD. I've got to say thank you to @mikeDnight for giving me some perseverance. I let the double star drift across my field of view umpteen times and experimented with the magnification. After a while I suspected that I could sense the B and the D star (if that's the way around the smaller companion stars are labelled) and Mike's sketch was a great help. In addition as it got darker and conditions perhaps a bit better I was able to boost the magnification to 200x and shortly after midnight I could see with certainty the double double. I can also confirm that Mike's sketch is spot on as far as I can see. In my case, of course, the view was a mirror image of his in the vertical plane. The smaller companion star that's between the two bright stars appears to point to the other smaller companion star on the outside of the double, if you see what I mean.

That was an excellent challenge and I was happy to get away from constantly viewing Jupiter and Saturn for half my observing session.

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That's a superb report David and its great to hear that, through perseverance, you had success. It certainly wasn't easy for me either, but rather than rushing from one object to another just having superficial glimpses, it pays to be patient. I'm so glad you managed to see the tiny companion after some careful study and I'm glad you could confirm my positioning.

Many thanks :thumbsup:

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1 hour ago, mikeDnight said:

That's a superb report David and its great to hear that, through perseverance, you had success. It certainly wasn't easy for me either, but rather than rushing from one object to another just having superficial glimpses, it pays to be patient. I'm so glad you managed to see the tiny companion after some careful study and I'm glad you could confirm my positioning.

Many thanks :thumbsup:

I think you did pretty well with just 100mm Mike - the S&T (Chris Lord algorithm) limit for unequal magnitude doubles would indicate that a split wouldn't be possible, although I've found the algorithm a bit pessimistic personally, and your scope should perform up to the laws of physics limits!.

Chris

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Hi Chris,

To be honest I pay little attention to the number crunchers and prefer to observe in ignorance the things I can't possibly see. :icon_biggrin:

Of course I'm not suggesting that either I or my telescope can see beyond the physically impossible, just that the impossible is in many instances much further down the line than that dictated by popular opinion.

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4 minutes ago, mikeDnight said:

Hi Chris,

To be honest I pay little attention to the number crunchers and prefer to observe in ignorance the things I can't possibly see. :icon_biggrin:

Of course I'm not suggesting that either I or my telescope can see beyond the physically impossible, just that the impossible is in many instances much further down the line than that dictated by popular opinion.

Oh yes - go for it, push the limits!

Personally I find that the limits published and accepted for nearly equal doubles work pretty well, after all there's a couple of hundred years of experience behind them, but that the quoted numbers for unequal doubles don't match my experience, albeit with long focus Maks and 'fracs.

Chris

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  • 3 weeks later...

Hi guys

Really interesting reading all these posts on such a challengingly double-double, and quite inspiring too! I'm not very experienced with observing binaries, I guess that there are many many much easier doubles/multiples to look at first! But in theory, what chance would you think that an ED80 would have with Struve 1964? 

Clear skies,

Donaldo :D 

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