The 60mm Doubles Project: An invitation to collaborate

[Neil_104]

I had a go at Epsilon Draconis last night and am happy to report I got a split. It was a lot more convincing than my views of Izar, with the secondary clearly seen as a star sitting on the first diffraction ring of the primary. I ramped the power straight up to 129x using my 7mm DeLite coupled with the 2.5x Powermate. Colours were creamy for the primary and bluish-grey for the secondary. I've since read that Hass describes the secondary as powder blue, and this is exactly the more artistic way of putting it!

Seeing caused the secondary to come in and out of view, at times disappearing, at other times as clear as day (or night I guess).

Once I had the split confirmed I then backed off the power to see how far out I could still see it:

PM + 9mm (100x) - split.
PM + 12.5mm (72x) - split, just about. Had I not seen it at 129x, and therefore knew what to look for, I think this would be less convincing.
7mm (51x) - seen as an extension to the primary.

And all this with the glare of my laptop screen a few meters away as I was imaging M57 at the same time for some astronomical multitasking! 

Whilst in the area I also took a look at the following:

STF 2241 (Psi Dra, Dziban) - easy split with 17.5mm (21x), best seen at 51x, colours were bright golden and a quite bright lime green secondary.
STFA 35 (Nu Dra) - appeared as two identical suns at 100x. Nice symmetrical, balanced view.
STF 2323 (39 Dra) - AB (3.6") were split at 51x. The C component looked very slightly lime green (I seem to see the colour lime green a lot). It needed more power to fully appreciate the split, so I went up to 72x with the PM + 12.5mm. Colours were mostly lost at this point, appearing cream, grey, grey. I can definitely recommend this one, it was a pleasant view.

Sat outside under the stars in shorts & t-shirt on a balmy summer's evening, with a beer, as my imaging rig busily worked away on M57. A fine evening.

[John]

39 minutes ago, Mr Spock said:

Now there's an excuse for a FS60 if ever I heard one 

I reckon my ED53 F/17 performs practically as well, maybe even a touch better 😉

I'll stick with my little 70mm F/6 ED travel kit as my smallest native aperture scope I think. I would not use 60mm enough to justify the investment in a little Tak, lovely though they are 🙂

 

Edited September 10, 2023 by John

[John]

2 hours ago, josefk said:

How do you make your aperture mask @John .....

 

The "mask" I'm currently using is simply the hole that is in the plastic dust cap, which has a diameter of 53mm. Simples 🙂

 

Edited September 10, 2023 by John

[The60mmKid]

50 minutes ago, Neil_104 said:

Sat outside under the stars in shorts & t-shirt on a balmy summer's evening, with a beer...

No wonder you had such a successful session. I also see so many more doubles when I'm observing with beer 😁

[jjohnson3803]

On 10/09/2023 at 04:57, The60mmKid said:

No wonder you had such a successful session. I also see so many more doubles when I'm observing with beer 😁

If I use binos while fatigued, everything is a double.  🥴

[lunator]

I have an old pair of Tasco Binos that have become mis-aligned so Albireo is a beautiful yellow and blue quadruple 😁

[MalcolmM]

Trying for Doubles in Cassiopeia

Doubles is not my first choice, but I'm keen to get more experience at it, as it is less constrained by light pollution. So, this report can be seen in it's context as a beginner's 🙂

My goal was to try and observe all the doubles in Cassiopeia mentioned in "Turn Left at Orion", with my FOA60Q on an iOptron AZMP; a very stable setup. I do not use this in 'goto' mode, I prefer the pain of star hopping! There is a great feeling of satisfaction in star hopping to a dim target and actually finding it!

The night was clear and very steady but poor transparancy. The main 'W' of Cassiopeia was visible with Kappa and Achird only just visible naked eye and Iota occasionally out of the corner of my eye.

First up was Achird as it is very easily found. This was an easy split with a 28mm Erfle (x32). The primary was a definite yellow, but I could not discern any colour in the secondary (according to 'Turn Left at Orion' it should be red). I swapped the 28mm to a 6mm (x150) Abbe Ortho and a third star appeared, roughly six times the distance from the primary as the secondary is. This third star, very dim and no colour, is not actually part of the Achird system but is shown in TLatO roughly SE of Achird. With the 6mm, the secondary was still showing no colour.

Next was Iota which, not easily seen with the naked eye, was easy in the finder. Nothing was visible in the 28mm. Using a Tak Abbe Ortho 9mm (x100) I could see a small right angled triangle of stars. The inner secondary (B) was sitting on a diffraction ring and looked smeared out along the ring a bit. The outer secondary (C) was very dim sitting outside the diffraction ring. No colour was obvious (I guess that makes them white which ties up with TLatO!). Putting in the 6mm, 'B' was less smeared in the diffraction ring. A Kokusai Kohki 5mm (x180) Orthoscopic dimmed the image such that 'C' was very difficult to see.

On to Struve 163 which proved tricky enough to find using the little triangle of stars just beyond Epsilon Cassiopeia. I recorded the primary as very red, which contrasts with the orange as mentioned in TLatO. The 'B' companion was easy to spot using the 28mm but I was not able to see the 'C' companion at all, in any of the eyepieces.

Next I tried for Burnham 1. Using the 28mm eyepiece and the little star char in TLatO, I was convinced I had the correct star but was unable to see any of the secondaries. There was a very dim star roughly 1/10th the FOV away from the primary. This would possibly tie up with the pair of stars to the SW of the primary in the 10' circle diagram in TLatO, but this is a complete guess.

This failure and the fact that I'm trying to navigate at roughly the zenith and getting quite cold persuaded me to call it a night. Very enjoyable though and I'm looking forward to trying for Struve 3053 and Sigma Cassiopeia another, hopefully more transparent, night where the colours are more obvious and I can see deeper.

Malcolm

 

[bomberbaz]

On 22/07/2023 at 22:28, The60mmKid said:

A call to all the 60mm refractor double star extraordinaires...

Over the years, I've spent many happy hours observing doubles with 60mm refractors. A while ago, I decided to set out on a quest that is equal parts ambitious, enjoyable, and unabashedly pointless—to observe and catalog every double star that can be observed with a 60mm refractor from my location (currently London). Here is the log that I am keeping of my observations:

https://docs.google.com/spreadsheets/d/18M8e2s9gzexgZFfJX9dTkQfAEbH5ahXds46rZTDF1bg/edit?usp=sharing

If you click on the "Project Description" tab at the bottom of the spreadsheet, you'll see a key for the symbols, terms, and sources that I'm using. At this time, I have logged about 80 doubles in Leo Minor, Canes Venatici, Corona Borealis, and Bootes. This is just a starting point, and it goes to show that there are enough doubles to keep small telescope owners engaged for years.

And so, I am inviting you intrepid 60mm observers to join the fun and post observations here. My hope is that this thread will serve as 1) a place for 60mm aficionados to enjoy sharing with each other and 2) a resource for those who wish to observe more doubles with their small telescopes. I'll keep updating my log and will also add posts here when I come across especially rewarding doubles. I invite other 60mm refractor observers (and admirers) to share their big enjoyment of their small scopes 😎

To close this introductory post, here's a picture of FOA-60Q dreaming about doubles in Bootes on a rainy London evening.

 

 

Hello all, decided to join in on this, I will be using a project rebuilt Prinz Astral 60mm F12 on a Skytee 2 with a 76mm F16 PAstral alongside to do instant revisits on objects that demand that little bit more.

All we need now are clear skies, oh erm 🤪🤣

Steve

[Neil_104]

On 24/10/2023 at 11:03, MalcolmM said:

Trying for Doubles in Cassiopeia

Doubles is not my first choice, but I'm keen to get more experience at it, as it is less constrained by light pollution. So, this report can be seen in it's context as a beginner's 🙂

My goal was to try and observe all the doubles in Cassiopeia mentioned in "Turn Left at Orion", with my FOA60Q on an iOptron AZMP; a very stable setup. I do not use this in 'goto' mode, I prefer the pain of star hopping! There is a great feeling of satisfaction in star hopping to a dim target and actually finding it!

The night was clear and very steady but poor transparancy. The main 'W' of Cassiopeia was visible with Kappa and Achird only just visible naked eye and Iota occasionally out of the corner of my eye.

First up was Achird as it is very easily found. This was an easy split with a 28mm Erfle (x32). The primary was a definite yellow, but I could not discern any colour in the secondary (according to 'Turn Left at Orion' it should be red). I swapped the 28mm to a 6mm (x150) Abbe Ortho and a third star appeared, roughly six times the distance from the primary as the secondary is. This third star, very dim and no colour, is not actually part of the Achird system but is shown in TLatO roughly SE of Achird. With the 6mm, the secondary was still showing no colour.

Next was Iota which, not easily seen with the naked eye, was easy in the finder. Nothing was visible in the 28mm. Using a Tak Abbe Ortho 9mm (x100) I could see a small right angled triangle of stars. The inner secondary (B) was sitting on a diffraction ring and looked smeared out along the ring a bit. The outer secondary (C) was very dim sitting outside the diffraction ring. No colour was obvious (I guess that makes them white which ties up with TLatO!). Putting in the 6mm, 'B' was less smeared in the diffraction ring. A Kokusai Kohki 5mm (x180) Orthoscopic dimmed the image such that 'C' was very difficult to see.

On to Struve 163 which proved tricky enough to find using the little triangle of stars just beyond Epsilon Cassiopeia. I recorded the primary as very red, which contrasts with the orange as mentioned in TLatO. The 'B' companion was easy to spot using the 28mm but I was not able to see the 'C' companion at all, in any of the eyepieces.

Next I tried for Burnham 1. Using the 28mm eyepiece and the little star char in TLatO, I was convinced I had the correct star but was unable to see any of the secondaries. There was a very dim star roughly 1/10th the FOV away from the primary. This would possibly tie up with the pair of stars to the SW of the primary in the 10' circle diagram in TLatO, but this is a complete guess.

This failure and the fact that I'm trying to navigate at roughly the zenith and getting quite cold persuaded me to call it a night. Very enjoyable though and I'm looking forward to trying for Struve 3053 and Sigma Cassiopeia another, hopefully more transparent, night where the colours are more obvious and I can see deeper.

Malcolm

 

Enjoyed reading your report Malcolm, and you certainly have a very nice scope to join in the fun with! I'll give all of these a go myself soon as well - Cassiopeia is mostly un-tapped doubles territory for me. I say soon - I kind of have to divide my 60mm time between imaging and double star observing. Last time out, Imaging M31 won the battle 😄

[Neil_104]

I had a look at a couple of doubles in Cassiopeia earlier this evening. Sky conditions weren't the best and it was difficult fine-focussing at times with explosions going off all around me...

Eta Cas
=>Easy split and best seen with my 7mm DeLite (51x). I saw the colours as yellowish-white and reddish-orange. Very nice, and the red secondary really was striking. Interestingly my 12.5mm Morph (29x) displayed the secondary as orange - no hint of red. Having done some reading up since on Eta Cas I didn't realise there were so many additional (but non-gravitationally linked) stars in the vicinity so I'll augment my sketch with the fainter members - at least, the ones I can see - the next time I'm out and see how faint I can go. I believe I've only caught component G (mag. 9.5) in my sketch so far.

Phi Cas
=>I've observed this cluster (NGC 457, the ET Cluster) many times in the past but until my recent foray into double star observing I had never really considered it a double star as such. Before, it was a star cluster with two bright stars. Now, it's a double star with associated cluster 😄 This one never ceases to amuse me, especially when ET is upside down and generally just larking about in space. I saw a yellowish-white primary and orangey-grey secondary, again with the 7mm.

Glad to be underway in Cassiopeia. Starting a doubles hunt in a new constellation feels a bit like pouring a new beer.

Bad analogy? Probably. Oh well 😄

Edited November 4, 2023 by Neil_104

[The60mmKid]

Thanks for the updates, friends. It makes me happy to see the thread alive. I haven't been able to spend any time observing lately due to a stressful period at work and the constant clouds. But I'm glad to know those doubles are still up there, waiting for me 😉😎

[Richard N]

I recently bought an Altair Astro 60mm finder. Any thoughts on how good it might be for doubles?  I bought it at Kelling and it’s been cloudy ever since. 

[The60mmKid]

9 hours ago, Richard N said:

I recently bought an Altair Astro 60mm finder. Any thoughts on how good it might be for doubles?  I bought it at Kelling and it’s been cloudy ever since. 

Please let us know! I had a similar finder that I liked a lot. It was especially enjoyable with the Edmund 28mm RKE eyepiece... like a miniature projection of the galaxy floating in front of one's eye. So, I like the idea of using such a finder for double stars, especially wider ones located in a rich field. 61 Cygni, anyone? 😍

[Mircea]

Richard

My opinion is that finder may have issues at resolving double stars because it is ... too big.

Why am I saying this ?

I have a similar finder, branded as BTC 60x232mm. I did not try it on double stars. But the objective is less than F/4 and it use an Amici prism, not very good for higher resolution.

But I have very good experiences with a 45x300mm refractor.

Below, I randomly choose examples from my observation log of double star observations with this 45mm  F/6.67 refractor used with a normal prism diagonal.

The 45mm aperture is not an issue to split Beta Mon as triple star or Theta Ori 1 /Trapezium as four star system, Gamma Del, Alpha Her. Of course, Epsilon 1-2 Lyrae was resolved as a double star.

 

I believe, the 60mm finder, as it is, should resolve Albireo, Theta Ser, Omicron Cyg, 16 Cyg, 61 Cyg, Beta Lyr, Psi Dra, Nu Dra, 16+17 Dra, STT 747, Mintaka, Sigma Ori as a double and many more such doubles.

Please let us know your results.

 

In the attachments we see my 45x300mm ''beer bottle'' refractor and a small part of objects/ double stars observed with it.

It was my first achromat lens in a time when here in Romania there was no telescope market and achromat objectives existed only in the wet dreams of amateur astronomers.

Only in 2011 I got my first astronomical 60x700mm lens, a donation from Brian Nordstrom, colleague on ''60mmtelescopeclub''. 

 

Mircea

Edited November 10, 2023 by Mircea