The 60mm Doubles Project: An invitation to collaborate

[The60mmKid]

22 minutes ago, lunator said:

That is an excellent result.

For the 60mm you should be able to split pairs separated by ~1.9" and a delta Mag of ~2-2.5.

I'll have a dig into the WDS to see if there are any suitable pairs.

Cheers

Ian

Please post the pairs here! And please do feel free to take a look at the spreadsheet I link in the first post. There are some good challenge pairs on there. (You can use ctrl + f to search for "challenge.") For example, here's a fun one:

STF 1768AB   Sep: 1.7    Mag 1: 4.98     Mag 3: 6.95    

Note:  300x  I certainly wasn't able to split this pair, but I was able to see B "peeking over" A, similarly to how Zeta Herculis looks through a 100mm scope. A fun 60mm challenge. Revisit with a larger scope.

[lunator]

I'll have a look. 

I have split STF1768 but it took x180 to get a nice clean split. This was using a 10" scope so not really a challenge 😁

[The60mmKid]

1 minute ago, lunator said:

I'll have a look. 

I have split STF1768 but it took x180 to get a nice clean split. This was using a 10" scope so not really a challenge 😁

Brought a gun to the knife fight, eh? 😾

[Mircea]

I got recently from a friend a Dialyt 25x56mm spotter. 

Like this one:

https://www.ebay.com/itm/225374231155

 

For now I cannot attache it to a tripod because the threaded hole  is bigger than the standard 1/4'' screw on my photo tripod.

So I tested the Hensoldt Wetzlar telescope holding in hand and propping against a window sill.

The Alcor-Mizar system was resolved big style, it was visible also the Sidera Ludoviciana, star located between Alcor and Mizar. 

Mizar was split, wide and clear.

What impressed me was the Dialyt splitting Gamma And A, BC with a separation of 9.5''.

As I remember I was needing a magnification of about 40x to split Almach on 60mm telescopes. Maybe I'm wrong.

Apart of that, Dialyt showed a decent image of M31 while M32 was a very small puff, nearby.

At ET Cluster/ NGC 457, the hand held telescope showed a faint haze around Phi Cas.

The Alpha Per Cluster and stars 29 per and 31 stars helped me to find out the apparent field of view of the eyepiece being about 63*-65*.

The actual field is 2.5*.

 

I hope to find soon a method to attach the Dialyt to a tripod. The image is very good, is promising a lot of fun.

 

Clear sky, Mircea

[StevieDvd]

1 hour ago, Mircea said:

I got recently from a friend a Dialyt 25x56mm spotter. 

Like this one:

https://www.ebay.com/itm/225374231155

 

For now I cannot attache it to a tripod because the threaded hole  is bigger than the standard 1/4'' screw on my photo tripod.

So I tested the Hensoldt Wetzlar telescope holding in hand and propping against a window sill.

The Alcor-Mizar system was resolved big style, it was visible also the Sidera Ludoviciana, star located between Alcor and Mizar. 

Mizar was split, wide and clear.

What impressed me was the Dialyt splitting Gamma And A, BC with a separation of 9.5''.

As I remember I was needing a magnification of about 40x to split Almach on 60mm telescopes. Maybe I'm wrong.

Apart of that, Dialyt showed a decent image of M31 while M32 was a very small puff, nearby.

At ET Cluster/ NGC 457, the hand held telescope showed a faint haze around Phi Cas.

The Alpha Per Cluster and stars 29 per and 31 stars helped me to find out the apparent field of view of the eyepiece being about 63*-65*.

The actual field is 2.5*.

 

I hope to find soon a method to attach the Dialyt to a tripod. The image is very good, is promising a lot of fun.

 

Clear sky, Mircea

You just need an adapter like this example off EBAY.  They are widely available and probably best obtained locally or via an Astro or Photo club/site/merchant in Romania.

 

[Neil_104]

I've been busy continuing with my double star observations, with almost 20 in the bag now. I've also invested in some added firepower for the titchy sixty: a 2.5X Powermate:

So I resumed my challenge to split Izar last night, fully confident I'd have it split, sketched and logged in a few mins and then onto the rest of the doubles on my list. And.....

....still couldn't split it 😕

This was with a 7mm DeLite plus the powermate for 129x. Geez, what's this gonna take??!

At this point I think I have the following options:

a) Give up.
b) In the words of Martin Brody in the film Jaws, "We're gonna need a bigger boat telescope".
c) Get a 5mm DeLite for 180x.
d) Wait for a night of such exceptional seeing that I could split stars far beyond the normal expected capabilities of a 60mm refractor.
e) Just say I did split it, hope no one notices, and move on.

I'm not a quitter, so option a) isn't going to be considered. 

This is a the 60mm project so getting that 5-inch I've got my eyes on just wouldn't be right. 

Option c) is tempting. Very tempting. I like that one a lot to be honest.

Since I live in the UK, I don't really fancy waiting 10, 20, (30?) years for option d) to roll around.

Option e. Hmmm, seems a little dishonest. Nope. Once I do finally split it, it'll be all the more satisfying.

So I think I'll give it a few more attempts with the 7mm, clean all the lenses (including my eyes), and hope for some seriously steady skies. All while thinking about that 5mm 🙂

[The60mmKid]

5 minutes ago, Neil_104 said:

I've been busy continuing with my double star observations, with almost 20 in the bag now. I've also invested in some added firepower for the titchy sixty: a 2.5X Powermate:

So I resumed my challenge to split Izar last night, fully confident I'd have it split, sketched and logged in a few mins and then onto the rest of the doubles on my list. And.....

....still couldn't split it 😕

This was with a 7mm DeLite plus the powermate for 129x. Geez, what's this gonna take??!

At this point I think I have the following options:

a) Give up.
b) In the words of Martin Brody in the film Jaws, "We're gonna need a bigger boat telescope".
c) Get a 5mm DeLite for 180x.
d) Wait for a night of such exceptional seeing that I could split stars far beyond the normal expected capabilities of a 60mm refractor.
e) Just say I did split it, hope no one notices, and move on.

I'm not a quitter, so option a) isn't going to be considered. 

This is a the 60mm project so getting that 5-inch I've got my eyes on just wouldn't be right. 

Option c) is tempting. Very tempting. I like that one a lot to be honest.

Since I live in the UK, I don't really fancy waiting 10, 20, (30?) years for option d) to roll around.

Option e. Hmmm, seems a little dishonest. Nope. Once I do finally split it, it'll be all the more satisfying.

So I think I'll give it a few more attempts with the 7mm, clean all the lenses (including my eyes), and hope for some seriously steady skies. All while thinking about that 5mm 🙂

Yeah, never quit! You can do it! The good news is that the 60mm refractor is resilient against bad seeing. In my opinion, 200x and up with a 60mm refractor is good for Izar, which is tricky because not every 60mm scope will handle that much magnification. And more good news: Izar will be easy with a 5" scope. Once you split it with the larger scope, you may find it easier to see both of the components (even if not fully separated) with the smaller scope. Izar, even when not cleanly split, is a lovely sight.

[John]

The separation with Izar is 2.88 arc seconds so well within a 60mm scopes resolution limit. It is the brightness difference between the two component stars (mag 2.58 and mag 4.81) that creates the challenge. 

Sirius is the most extreme example of this. 

Keep at it - on a steady night, you might just crack it !

 

[IB20]

I found Izar is a very easy split once I’d done it once. Even in an 8” dob in bad seeing I found it tough but one night it split very easily in my 3”, absolutely beautiful colouration on the secondary and one of my favourite doubles now.

[Stu]

Likewise I rarely struggle with Izar even in small scopes. It splits in my FS-60C, the Zeiss Telementor (63mm) and TAL Alkor (65mm newt). Report here:

 

[John]

I can split Izar with my 70mm refractor. My 60mm is still up in the loft so I don't know whether that will do it.

Delta Cygni is another favourite test for the smaller aperture at this time of year.

Occasionally I've stopped down my ED120 to a 52mm F/17.3 and I have been surprised what that will resolve. I can't recall if Izar is one that I've tried with that setup though 🤔

[Neil_104]

Ah ok, following the thread Stu posted, there's a mock-up of how Izar looks through a 60mm:

Yes, that's what I'm seeing. I thought it was bad seeing and low altitude causing some kind of weird aberration, but seems it might actually have been the secondary. D'oh!

I'll double check the PA next time I'm out.

[John]

It will be interesting when Orion and M42 are showing well again. Who will be the 1st to get E & F Trapezium with a 60mm ? 😁

[IB20]

I have bagged E with the 76 but not managed F yet, it all depends on good transparency. Impressive feat for a 60 i’d say but the FOA-60Q owners might have a chance.

[Stu]

9 hours ago, Neil_104 said:

Ah ok, following the thread Stu posted, there's a mock-up of how Izar looks through a 60mm:

Yes, that's what I'm seeing. I thought it was bad seeing and low altitude causing some kind of weird aberration, but seems it might actually have been the secondary. D'oh!

I'll double check the PA next time I'm out.

I see it much more clearly than that. As I recall it, the primary is a beautiful, well defined airy disk and the secondary shows clear separation even though on the first diffraction ring. I will check again next chance I get.

[Mircea]

StevieDvd

 

Thank you for the useful tip ! I will look for those.

 

John

It is fun you mentioned stopping down to 52mm your 120mm ED.

This is precisely what I have done last night with my SW Classic 250P Dobsonian. It has a 52mm hole in the cap.

I was experimenting more times with this 52mm F/23 extra-axial reflector in the past.

Izar was split last night at 150x obtained with the Baader Mark III zoom eyepiece.

This is a fantastic instrument. The Airy discs are huge and at 100x the colors of Albireo, Garnet Star and Almach are well saturated. A feast !

 

This is how it look the mighty 52mm F/23 telescope. The picture was taken March, last year ...

You have everything: good eyepieces, finders, strong mount. Just not recommended for the faint hearted ones suffering of aperture feaver. 🤩

However, it showed last night a dim but visible M56 cluster also.

 

Clear sky, Mircea

 

[Mr Spock]

If we get some clear skies, baby Tak is ready to go. As usual I'll be doing drawings 

[Neil_104]

4 hours ago, Stu said:

I see it much more clearly than that. As I recall it, the primary is a beautiful, well defined airy disk and the secondary shows clear separation even though on the first diffraction ring.

From memory I was seeing the secondary as being quite well defined, though very fuzzy, and as you say on the first diffraction ring. I suspect me overlooking it was just a case of not knowing what to expect from such a close double, along with the magnitude difference between the primary and secondary, all at relatively high magnification.

I have of course looked at many doubles over the years, but just in a casual manner. This is the first time I've gone at them in any "serious" and systematic way. And I'm loving it it has to be said!

However, even with the nut of Izar on the verge of being cracked, the 5mm DeLite is still going to be considered 😄

 

Edited August 28, 2023 by Neil_104

[John]

I find my Nagler 4mm-2mm zoom an really valuable tool for double star splitting. The click stops are at half mm intervals but you can use the points in between those as well.

I can see that the Svbony 8mm-3mm zoom could be a really good (and less than TV expensive) eyepiece for double star observing as well.

Iota Cassiopeiae is a lovely close triple which small scopes and high magnifications can have fun with.

 

Edited August 28, 2023 by John

[Neil_104]

Yes I can definitely see the convenience a zoom would provide, trouble is they don't have adequate eye relief. The Nagler zooms and the SV Bony have 10mm, which is way too short for me. I need at least 15mm for proper comfort....not due to wearing glasses but due to pesky long eye lashes!!

I am considering the Baader zoom, that's got 12-15mm eye relief and so for the most part would be fine. I could use that for the initial find and zoom, and then switch to the lower FL eyepieces if required. Trouble is, I really like my Morphs and don't like the idea of them being made almost redundant by the zoom. We'll see.

Edited August 28, 2023 by Neil_104

[Stu]

On 28/08/2023 at 14:20, Neil_104 said:

From memory I was seeing the secondary as being quite well defined, though very fuzzy, and as you say on the first diffraction ring. I suspect me overlooking it was just a case of not knowing what to expect from such a close double, along with the magnitude difference between the primary and secondary, all at relatively high magnification.

I have of course looked at many doubles over the years, but just in a casual manner. This is the first time I've gone at them in any "serious" and systematic way. And I'm loving it it has to be said!

However, even with the nut of Izar on the verge of being cracked, the 5mm DeLite is still going to be considered 😄

 

I’ve just done a bit of an experiment comparing the FS-60C with FC-76DCU on Izar. Seeing was pretty ropey actually and that made it much trickier than I recall when I wrote that report.

In the 60mm, the secondary was pretty hard to spot, just a lump on the diffraction ring which was jumping around with the seeing. That was with the Nag zoom at 3mm (x118) and a Vixen 2.4mm HR planetary (x148). I didn’t try with the CQ Extender but that may well improve things as well as giving a higher mag.

In the 76mm (sorry to mention on this thread (😉), the secondary was very clearly a blue/grey disk on the diffraction ring with very obvious separation. Agreed this was at x190 and x237 due to the longer focal length but the resolution difference look obvious to me.

I will definitely try again with better seeing conditions and with the 60Q which will even up the mags and likely tighten the stars in the 60mm. Fun exercise.

[Mr Spock]

Here are a few from last night I've just posted in this section.

 

 

[The60mmKid]

55 minutes ago, Mr Spock said:

Here are a few from last night I've just posted in this section.

 

 

Fantastic sketches! Just like looking through the eyepiece 😊

[Stu]

Nice sketches Michael, how did you generate them, electronically I guess? Works well. Which Barlow were you using? Couldn’t get to x162 with either a x2 or x2.5?

Separations look a little large vs the main split when compared with SkySafari.

Regardless, hope you enjoyed the 60 on the doubles and the nice big airy disks?

[Mr Spock]

3 minutes ago, Stu said:

Nice sketches Michael, how did you generate them, electronically I guess?

I draw them in PaintShop Pro from sketches made at the eyepiece on paper with pen. The PSP drawings are then added to an Excel worksheet - one sheet per double - where I can add the text.