Stupid newbie question : What is the fuss about splitting doubles ?

[661-pete]

I recall trying - and failing - to split either component of the Epsilon Lyrae pair with the 10" newt. They are not the easiest of binaries but at 250x it should have been possible, the separations are 2.5 arcsec. and 2.3 arcsec. respectively. This was in the early days soon after I'd first got the 'scope and was trying things out, but maybe (a) the seeing wasn't perfect, and ( my collimation was a bit out. You really do need spot-on collimation to resolve a close binary. I ought to try again when I get another chance.

[kniclander]

I love doubles:) - just read some of Smyth's descriptions of the colours and use your imagination to see what colours you can see and wonder that you will see colours that you will never see on earth ...

I do however much prefer them through my ed80 than my 10" newt as the stars are much much sharper. I can split both of the double doubles in my newt at about 150x reasonably easily (the real difficulty is actually focussing cos the scope vibrates a lot) but in the frac the view is just so much cleaner and more satisfying and I can see individual colours in each star...

[brianb]

I recall trying - and failing - to split either component of the Epsilon Lyrae pair with the 10" newt. They are not the easiest of binaries but at 250x it should have been possible,

Assuming the seeing was at all reasonable it should have been a doddle. The "double double" yielded to the poor quality 60mm refractor I had in the late 1960s, x56 though a higher power was a bit better (so say my notes). Suggest collimating your scope.

[Catanonia]

ok if I was to give this a go for the 1st time, what would be a good beginner set of targets to split ?

[John]

ok if I was to give this a go for the 1st time, what would be a good beginner set of targets to split ?

This web site provides a useful starter list:

Double Star Club Observing List

John

[Astro_Baby]

I'm with Lulu and Ashelight on it. I dont do it for the math or gadgetary or the physics. I do it for the sense of wonder. As Lulu said we are all made of star stuff - we are stardust and to stardust we return.

I do astronomy for the WOW factor. Your seeing things millions of miles and millions of years ago. I dont have a particular passion for doubles, or variables or even planets. I have a wonderment at ALL of it.

[Robert Anstruther]

I think it's all of the above! For me its everything, the awesome wonder, the maths and physics, the art and the engineering. We came from it, and we will go back to it. We wonder in its marvel by the use of instruments we created.

I think what lulu said was spot on, most people get an immense deep satisfaction from astronomy, be it from one thing or another.

[ashenlight]

I'm with Lulu and Ashelight on it. I dont do it for the math or gadgetary or the physics. I do it for the sense of wonder. As Lulu said we are all made of star stuff - we are stardust and to stardust we return.

I do astronomy for the WOW factor. Your seeing things millions of miles and millions of years ago. I dont have a particular passion for doubles, or variables or even planets. I have a wonderment at ALL of it.

Puts things into perspective doesn't it however rubbish your day is being I just remember... the stars are always there, the sun will always come up (queue pedantic comments about the life of stars and their inevitable demise ) Looking at doubles is just another one of those 'wow' moments for me - and the cosmos is jam packed with them. Just gotta find the one that floats your boat

[lulu57]

I'm glad I'm not alone in valuing an emotional response to the stars.

I know that without rigorous scientific and technological thinking, we would never be able to make these discoveries and we would never be able to go into space.

But it's the emotional response which guides us in deciding what are the right things to do with the new knowledge we've acquired.

I'm aware that I'm slowing disappearing into my own navel in advocating emotional intelligence.

I do apologise.

Give me five minutes and I'll be thinking about clothes and make up again (as per).

[Athena]

I'm a complete newbie too :-(

Having recently bought myself a telescope I decided to test it by looking a Mizar. At low magnification I could clearly see Mizar and Alcor but when I stepped up the magnification I was able to see Mizar A and B.

At first I wasn't sure what I was seeing but with help from this forum I know know.

I'm now looking forward to my next clear night and guess what I will be looking for? Yep, doubles.....

Nikki

[661-pete]

Mizar is a good double to start out with (I mean the two components of Mizar itself - not the Mizar Alcor naked-eye pair of course ). Not too close (about 14 arcsec), a reasonable test of your equipment and ability, easy to find and visible all the year round.

Izar (not a typo, this really is how it's spelt, a totally different star aka Epsilon Bootis). At less than 3 arcsec more of a challenge, but well worth it when you do split it (I've viewed it through someone else's big SCT).

And don't pass up Albireo if you haven't already had a look at it. OK I suppose many serious double-observers dismiss it as 'too easy', it's true that it is one of the easiest binaries in the sky, but don't miss it out for that reason! The colours are spectacular.

[Catanonia]

Mizar is a good double to start out with (I mean the two components of Mizar itself - not the Mizar Alcor naked-eye pair of course ). Not too close (about 14 arcsec), a reasonable test of your equipment and ability, easy to find and visible all the year round.

Izar (not a typo, this really is how it's spelt, a totally different star aka Epsilon Bootis). At less than 3 arcsec more of a challenge, but well worth it when you do split it (I've viewed it through someone else's big SCT).

And don't pass up Albireo if you haven't already had a look at it. OK I suppose many serious double-observers dismiss it as 'too easy', it's true that it is one of the easiest binaries in the sky, but don't miss it out for that reason! The colours are spectacular.

cheers might give them a go soon depending on the weather.

[Athena]

Izar (not a typo, this really is how it's spelt, a totally different star aka Epsilon Bootis). At less than 3 arcsec more of a challenge, but well worth it when you do split it (I've viewed it through someone else's big SCT).

And don't pass up Albireo if you haven't already had a look at it. OK I suppose many serious double-observers dismiss it as 'too easy', it's true that it is one of the easiest binaries in the sky, but don't miss it out for that reason! The colours are spectacular.

It would seem that the "New Telescope Curse" has passed Yet another clear night in London town and I'm off out to find Izar and Albireo.

[LaVey]

I had a while splitting doubles... I enjoy the colour variations.. here is a pic from a while back when I only had an LPI for imaging:

[lulu57]

"Only an LPI"?

Seems well fitted to the job to me!

I like the pics - thanks for posting them.

[Catanonia]

Well did a bit more splitting last night for last 5 mins.

Split the double in Hercules with no problems. That makes 2 now

[Ash2020]

Sorry to bring this down to an even more stupid question but, what qualifies a pair of stars to be a double? Aren't there so many stars that are very close together?

It slightly puts me off when I realise that there is so much that I don't know. I wish I could see it as a challenge!

[Mr Spock]

Observing doubles is one of those things you can't explain. They are fascinating, or they aren't.

Variable stars are the same. There's nothing more satisfying than producing a light curve of your own. It's easy to do too, and you don't need fancy kit.

Oh, and then there's the skill level with variables. It's amazing how accurate you can be at estimating magnitudes. Back at my best I successfully detected the seconday minima of WZ Cass. That's only -0.1 Mag...

[Macavity]

Sorry to bring this down to an even more stupid question but, what qualifies a pair of stars to be a double? Aren't there so many stars that are very close together?

It slightly puts me off when I realise that there is so much that I don't know. I wish I could see it as a challenge!

The conventional definition of a double (multiple) star is that there exists a PHYSICAL association, between two (or more!) stars. Mutual gravitation causes them to ORBIT around one another. In some cases, this is a clear association. Stars may be separated by a few million miles, a few AU's (qv), tenths of light years etc. Orbital periods vary from mere hours, to thousands (millions!) of years. In other cases, association may be more tenuous, with little relative motion over a human timescale.

In addition, there are the CHANCE "line of sight" doubles. These have no physical association. They may be tens, hundred, thousands of... light years apart! Yet, these are still seen as interesting - Through close spacing, colour contrast etc. ...

[Mr Spock]

Sorry to bring this down to an even more stupid question but, what qualifies a pair of stars to be a double? Aren't there so many stars that are very close together?

It slightly puts me off when I realise that there is so much that I don't know. I wish I could see it as a challenge!

Doubles are when stars orbit each other, rather than being line of sight. They change distance and position angle over time, though in some cases that may be a long time.

[twotter]

I like to observe just about everything and anything that's up there (behind the clouds).

Some months ago I had a wonderful evening where I concentrated on double stars - jewels in the night sky. It was so enjoyable that I've now got myself a zoom EP to try and go from single star - double star - single star - double star

[John]

I love splitting challeging double stars

It's a test of the observing conditions, the scope and myself and I find it very rewarding indeed. It's also frustrating quite often, especially when you don't get the results you anticipate !.

I've also been in the hobby long enough to have witnessed visible changes in the position angle and separation of a number of binaries - Porrima in Virgo for example.

There are so many aspects to the hobby though so it's not surprising that some won't hold much interest for everybody.

[Moonshane]

and Double stars gives him a astronomy option

this is an excellent point (in the voice of Sid the sloth from Ice Age).

I love the moon and planets and am lucky enough to live where although LP is bad (I am in a magenta area on one of those light pollution maps) my observing position is surrounded by gardens so it's not bad for DSOs etc - eg. I have seen the Veil (albeit with an Oiii filter) from my garden and M33 is a binocular object.

BUT if you live in a town centre or where LP is really bad and many DSOs are not an option, then solar system objects might get slightly repetitive. in these circumstances doubles are great fun.

for me I really like them and usually combine them with other targets in a night; I sometimes try and 'do' all the showy doubles in a constellation in a night. like with other objects, it's the thrill of the chase, the challenge of seeing difficult doubles with an obvious separation and yeah, OK, it's the lister in me too.

[Ash2020]

Wow, how on earth can anyone say with certainty that two stars are gravitationally linked with a period of thousands of years? Astonishing!

The conventional definition of a double (multiple) star is that there exists a PHYSICAL association, between two (or more!) stars. Mutual gravitation causes them to ORBIT around one another. In some cases, this is a clear association. Stars may be separated by a few million miles, a few AU's (qv), tenths of light years etc. Orbital periods vary from mere hours, to thousands (millions!) of years. In other cases, association may be more tenuous, with little relative motion over a human timescale.

In addition, there are the CHANCE "line of sight" doubles. These have no physical association. They may be tens, hundred, thousands of... light years apart! Yet, these are still seen as interesting - Through close spacing, colour contrast etc. ...

[valleyman]

Nobody mentioned Castor yet. was looking at it last night with 10mm plus x2. and could make out all its components.................Doubles and multipes do it for me.