Double stars are good friends

[The60mmKid]

They're always here for you.

I recently moved to London, and although I was (and am) so chuffed (I learned this word from watching the Bake Off) about the move, I had begun to mourn the loss of dark skies months ago. Two nights ago, I pointed my scope at M11 and M13 and felt shocked to see vague hints of the brilliant swarms of light I've come to know.

But the doubles are still there, showing up as they always have. It's comforting to move across the world and still see the Izar you've always known. I'll have to accept that I probably won't see M8 again soon, but Nu and Epsilon Draconis are still up there, faithful as ever.

I wish more beginners knew what a joy observing doubles can be. I feel like we'd lose fewer astronomers to discouragement... and imaging (sorry, had to, just kidding).

Thanks for reading 🤩

[John]

It all started with Algieba (Gamma Leonis) for me. My little 60mm refractor made it look so beautiful 🙂

My skies are not bad here but I always throw a few favourite double stars into an observing session 👍

The Star Splitters website is one of my favourites - real enthusiasts and wonderful descriptions of their observing adventures:

Star-Splitters (wordpress.com)

Edited June 25, 2023 by John

[callisto]

17 hours ago, John said:

It all started with Algieba (Gamma Leonis) for me. My little 60mm refractor made it look so beautiful 🙂

My skies are not bad here but I always throw a few favourite double stars into an observing session 👍

The Star Splitters website is one of my favourites - real enthusiasts and wonderful descriptions of their observing adventures:

Star-Splitters (wordpress.com)

Thanks for heads up on star-splitters site... very useful 👍

[Spile]

I totally agree with the sentiment. Doubles make for brilliant targets.

[wookie1965]

I am mostly a double star man I do look at clusters and planetary nebulas but my lists are 90% double stars I have loads of lists from various outlets. 

[glafnazur]

3 hours ago, wookie1965 said:

I am mostly a double star man I do look at clusters and planetary nebulas 

Same for me. I think I've only known one other member of my local astro society who liked looking at doubles,. For some reason or another most people just don't seem to like looking at doubles 🤔 

[wookie1965]

7 hours ago, glafnazur said:

Same for me. I think I've only known one other member of my local astro society who liked looking at doubles,. For some reason or another most people just don't seem to like looking at doubles 🤔 

With light pollution if you dont live in a dark site its a no brainer and there are some lovely doubles and multiples out there. The joy of splitting a tight double is like looking at Saturn for the first time.

[Mr Spock]

The Moon when it's up, and doubles when it's not. That sums up my interests. I don't know what it is about doubles but I never tire of them - even after 50+ years!

[badhex]

On 26/06/2023 at 00:05, The60mmKid said:

They're always here for you.

I recently moved to London, and although I was (and am) so chuffed (I learned this word from watching the Bake Off) about the move, I had begun to mourn the loss of dark skies months ago. Two nights ago, I pointed my scope at M11 and M13 and felt shocked to see vague hints of the brilliant swarms of light I've come to know.

But the doubles are still there, showing up as they always have. It's comforting to move across the world and still see the Izar you've always known. I'll have to accept that I probably won't see M8 again soon, but Nu and Epsilon Draconis are still up there, faithful as ever.

I wish more beginners knew what a joy observing doubles can be. I feel like we'd lose fewer astronomers to discouragement... and imaging (sorry, had to, just kidding).

Thanks for reading 🤩

I came late to appreciating doubles which may seem strange as I have lived with Bortle 7 or 8 for the last 18 years! As you mentioned, it's comforting to know that even if the skies aren't behaving, doubles will, in many cases, be there for you nonetheless.

I can't say I have hundreds under my belt but I do maintain a list of doubles that I want to look at, and have used numerous sources to hunt down potential targets, including the excellent Discovering Double Stars book by @Ags

[Mr Spock]

I started out with the Cambridge Double Star Atlas and Double Stars for Small Telescopes (Sissy Haas), both excellent. As I got more serious I realised that wasn't enough, especially if you want to go faint or find more obscure doubles.

So now I make my own charts. I print out various sized from Cartes du Ciel, with WDS enabled, with size depending on whether it's for the 4" or the 12", and then colour code the ones I want. My colour codes are:

1.14" to 2.99"
3.00" to 9.99"
10.00" to 29.9"
30.00" and over

My charts for Hercules -

For the 4", which is what these charts are for, if the they are tight I add the separation. Such as Σ2094 1.1 or β629 1.2. I used to put on the magnitude difference but now I don't bother. It makes it interesting and removes any bias.

[Ratlet]

Every time I see @Mr Spock way of marking up his charts I think it should be a sticky.

I've got @Ags double star book and it's a great beginner resource for double stars.

Biggest problem for me with doubles is I've got reasonably dark skies and there is so much up there to look at.

Thinking back to when I started as a newbie, for me doubles suffer from the same issues as globular clusters:

They don't photograph so well. 

It took me the longest time to realise that visual is not the same as astrophotography and with astrohpotography being so prevalent it kind of skews the perception of what to look at.

Glad I realised my mistake though.

[Mr Spock]

Light pollution here thanks to the new LED streetlights is so bad I can barely make out Hercules 

[Space Hopper]

And one obvious question to this thread is :

What is an optimal scope for doubles, taking in typical UK seeing ?

[Mr Spock]

3 minutes ago, Space Hopper said:

What is an optimal scope for doubles, taking in typical UK seeing ?

For me it's more about convenience - which is why I mostly use the 4". The 12" is big and bulky, but, has an airy disk a third the size. So even when seeing isn't so good it out performs the 4". 

I would have thought your TEC140 would be perfect 👍

[Coco]

Good watching although you already may have seen it, if your starting out its worth a watch

 

[John]

1 hour ago, Space Hopper said:

And one obvious question to this thread is :

What is an optimal scope for doubles, taking in typical UK seeing ?

For me a 100mm-130mm refractor is the optimum double star scope.

Larger apertures have the potential to resolve tighter splits of course but personally I prefer the clean, almost clinical presentation of the star images that refractors give. 

I have used mak-cassegrains and mak-newtonians that have given very good results as well I should say. Almost "refractor-like" 🙂

Edited July 5, 2023 by John

[Space Hopper]

Its very good ; its the users eyes that are not so good.

 

I've read the Tak FOA 60-Q (with 1.7x extender - F/15) is the best double star scope out there, pound for pound.

[John]

Again, speaking personally, I find apertures less than 100mm a little limiting for double stars although they do present them really well and many resolve fully up to their theoretical limits of course.

 

 

[Ratlet]

43 minutes ago, Coco said:

Good watching although you already may have seen it, if your starting out its worth a watch

 

The RASC do some fantastic YouTube content for visual observing.  

[Mr Spock]

I used to have a premium optics 140mm Mak which was excellent at doubles. A nice tight airy disk and virtually no diffraction ring.

[Ags]

2 hours ago, Mr Spock said:

Light pollution here thanks to the new LED streetlights is so bad I can barely make out Hercules 

Same here. I can - barely - make out the Hercules 'keystone' asterism on a good night.  Four nights out of five it is undetectable. It was easier a decade ago I think.

[Stu]

1 hour ago, John said:

For me a 100mm-130mm refractor is the optimum double star scope.

Agreed! I love the presentation of stars in these scopes, and a lot of the time they will resolve about as much as is possible. I’ve still to give my 128 a good go at some doubles but am looking forward to it 👍

1 hour ago, John said:

Again, speaking personally, I find apertures less than 100mm a little limiting for double stars although they do present them really well and many resolve fully up to their theoretical limits of course.

Though limited, I think doubles within reach of these scopes are beautiful to look at. Because the airy disk size is much bigger than with a larger scope, this seems to hide all the messiness caused by the seeing and so you are left with wonderful round ‘ball bearings’ of various colours against a (hopefully!) dark background. Stars like Izar look fab in my little Telementor (63mm) for example 👍, with the secondary sitting on the first diffraction ring, looking like a gem on a ring 💍 

[Mr Spock]

2 hours ago, John said:

For me a 100mm-130mm refractor is the optimum double star scope.

1 hour ago, John said:

Again, speaking personally, I find apertures less than 100mm a little limiting for double stars although they do present them really well and many resolve fully up to their theoretical limits of course.

I've never used the 60mm for doubles; the presentation on the 100mm is so good there's not much could tempt me away. I'd fancy a TOA-130 except the size and weight (and needing a new mount) would put me off.

On the other hand, splitting a 0.5" double with the 12" has a lot of satisfaction to it. 1" doubles separated by a huge space is a sight to see. However, the bulk and awkwardness of the scope makes it a challenge at times.

There are so many options which work I think everyone can gain a lot of double star pleasure from what they have. Even my old 120mm achro makes a good fist of it.

[Stu]

1 hour ago, Mr Spock said:

I've never used the 60mm for doubles; the presentation on the 100mm is so good there's not much could tempt me away.

Try it, you might like it! 👍

[Stu]

1 hour ago, Mr Spock said:

1" doubles separated by a huge space is a sight to see.

What sort of mag do you use to see that? Interested to hear the definition of huge, relative to the airy disk size?