Double stars are good friends

[John]

I've struggled with sub-arc second splits even with my 12 inch dob. I think it must be my eye and / or local seeing limitations perhaps ?

I have got a few but mostly with the 130mm refractor which shows very "clean" star disks even at stupidly high magnifications. I've not managed anything below around .8 arc second as far as I recall.

On the other hand, I seem to do quite well with the highly uneven brightness stuff like Sirius and Anatares. "Swings and roundabouts" I suppose 😏

 

[Mr Spock]

1 hour ago, Stu said:

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

x460

[Mr Spock]

Of course 'huge' is an exaggeration. Plenty of space between is more accurate 

[Mr Spock]

28 minutes ago, John said:

On the other hand, I seem to do quite well with the highly uneven brightness stuff like Sirius and Anatares. "Swings and roundabouts" I suppose 😏

I've yet to see Antares, but I did get 0.7" easily with the C9.25. I get Sirius occasionally. Interestingly I find Sirius easier with the 4" than the 12"; it's down to the glare I suppose.

As you say, swings and roundabouts.

[John]

I've never found anything closer than, say, 1.2 arc seconds is what I would call "easy" what ever scope I've been using. I have always found splitting sub-arc second doubles very hard to be honest. 

 

Edited July 5, 2023 by John
Grammar !

[glafnazur]

5 hours ago, Ags said:

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.

sadly I have to say it is the same here  

[Franklin]

7 hours ago, Ratlet said:

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

My skies aren't great but the aspect from my back garden looking south over fields is, so I tend to just view in the same direction, namely SE to S to SW. Because of all this, whatever constellation is approaching the meridian at the time I'm out is where I seek my quarry. Doubles, asterisms, DS objects and of course planets and luna when they're about. I think it was a post from Daniel Mounsey over on CN where I first heard the phrase "constellation mopping", which is sticking to observing in one constellation. With this idea not only are you observing when the targets are at their best ie. highest in the sky as the constellation transits the meridian but it also re-enforces your knowledge of the sky. There is so much to see in most constellations that I favor this technique over panning around the entire sky willy-nilly.

[John]

7 minutes ago, Franklin said:

..... I think it was a post from Daniel Mounsey over on CN where I first heard the phrase "constellation mopping", which is sticking to observing in one constellation. With this idea not only are you observing when the targets are at their best ie. highest in the sky as the constellation transits the meridian but it also re-enforces your knowledge of the sky. There is so much to see in most constellations that I favor this technique over panning around the entire sky willy-nilly.

An excellent approach I find.  

[Franklin]

15 minutes ago, John said:

An excellent approach I find.

It works for me, not having great skies and also using smallish aperture refractors, deep-sky targets for me tend to be the usual suspects so double stars are a great way of hanging around the same area. There are more doubles up there than you could see in a lifetime and the CDSA (which I think I got from you John) is my roadmap. It's a great way of pushing your optics as well and I'm amazed at how the Vixen HR range has pushed the boundaries of conventional "max mag" theory.

[John]

42 minutes ago, Franklin said:

... It's a great way of pushing your optics as well and I'm amazed at how the Vixen HR range has pushed the boundaries of conventional "max mag" theory.

I didn't think my 2-4mm Nagler zoom would get much use but I'll wear the thing out at the rate I'm going !

 

[The60mmKid]

On 05/07/2023 at 10:51, Space Hopper said:

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.

I've logged over 100 doubles with my FOA-60Q, and that's only in 3-4 constellations. When I've run out of doubles it can resolve, I'll have logged over 1,000. So, I certainly love mine as a double star scope.

But as others have noted, aperture expands the number of doubles that are resolvable... and it also creates a more aesthetically pleasing experience oftentimes. I enjoy pushing my 60mm to its limits on doubles, but then I love going back to the same objects using a 5-6" scope. It's a whole different view. And again, for every double the FOA-60 can resolve, there are so many more within the grasp of a larger scope.

I also agree with the aforementioned note about seeing conditions. Too large an aperture can work against us on doubles if the seeing doesn't support it. Someone mentioned you have a TEC-140? That's a reeeeaaaalllly sweet doubles scope! Want to trade for my FOA-60Q? ☺️

[Space Hopper]

I'd better not...........😀

I'm mainly a Lunar / Planetary guy with it to be honest.

Still feeling my way around with doubles. I have Agnes' double star book to help with that.

Before, it was just the 'usual suspects'.  My favourite has always been the Alcor / Mizar double. Its a beautiful sight once you crank up the power.

Also had a lovely split of the double double last month at our local dark site. I've split it plenty of times before, but that last time it looked textbook.

Always helps though when things are at a decent altitude.

Antares and Sirius will always be ultra difficult for me here at 53ºN.  And factor in Midlands seeing conditions as well.....

[The Lapwing]

On 02/07/2023 at 23:58, 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 🤔 

I blame Hubble

[jjohnson3803]

(Most) galaxies are right out for me at home as are a lot of less bright emission nebulae, so I've been mainly concentrating on open clusters.  Globulars are marginal at best with my scopes. 

A few months ago I started trying some wider doubles and they're slowly taking up more of my observing time.  The objects obliterated by LP here will have to wait until I can get out to a dark site I guess.

There are double star lists all over the place, but I'm wondering if the Cambridge atlas would be a good thing to have.