Eyepiece for double stars

[Starfleet]

Hello group,

I have a basic Meade astrometric eyepiece that I was going to use to measure simple double stars - and I mean just the very wide and easy pairs. Is there a better eyepiece available that people use for double stars?

Also I was wondering where you'd send your information if you accidentally discover a new double star. Can you check if a double star is already discovered as it were, like in a catalog?

[neptuneblue]

What about the 3.8mm Parks eyepiece for double stars?

[Merlin66]

A different alternative you might wish to consider...

A webcam can be used to give almost as good ( and in some cases, better) measurements of double stars than the astrometric eyepieces. Florent L. has developed a software program called "Reduc"

REDUC HELP

a free copy can be obtained by emailing the author

florent_losse@yahoo.fr

To assist in identifying double stars, I'd recommend Carte du Ciel. There are many double star catalogues which it can read and display.

[albedo0.39]

Speaking of double stars, why is it general knowledge that large aperture dobsonians are not that good at splitting doubles - despite the dawes limit ?

[Doc]

Expensive but perfect for the job.

Specialist - Baader MicroGuide Illuminated Reticle Eyepiece

[Starfleet]

Speaking of double stars, why is it general knowledge that large aperture dobsonians are not that good at splitting doubles - despite the dawes limit ?

I think Dobsonians are not suitable, because they dont have the clock drive. If you want to measure the stars positions it pays to have a Dob mounted onto the tripod to become a Newtonian,. The thing I find is at high magnification the stars drift FAST across the fov...

[Starfleet]

I actually borrowed my reticle eyepiece from a friend. It's this one from meade:

Meade MA 12mm Illuminated Reticle Astrometric Eyepiece 1.25 Inch Wireless - Telescope Eyepieces at Telescopes

[Merlin66]

You can always build a double imaging eyepiece from a small slip ( about 1mm thick) of Iceland Spar ( Calcite crystal)

I have one I made almost 20 years ago, based on a 1.25" x 25mm extension tube, mounted into a 150mm circular perspex protractor.

I can post photos if there's any interest.

Allows easy measurement of double stars with 4 -15 sec separation.

[Starfleet]

You can always build a double imaging eyepiece from a small slip ( about 1mm thick) of Iceland Spar ( Calcite crystal)

I have one I made almost 20 years ago, based on a 1.25" x 25mm extension tube, mounted into a 150mm circular perspex protractor.

I can post photos if there's any interest.

Allows easy measurement of double stars with 4 -15 sec separation.

Ooh it sounds v. interesting. Please Post it. I would like to see it:hello2:

[Merlin66]

Got relatives visiting all weekend!

I'll see if I can get some images together tomorrow/ Monday....

[Merlin66]

Managed to sneak a few minutes....

Any questions, just ask!

[Starfleet]

Lovely. Neat inexpensive solution if you're not able to buy one. I remember a few decades ago when telescopes and all their accessories were waaayyy to expensive. A friend of mine used spectacle lenses and toilet roll to make a simple telescope. It even let you glimpse the moons of Jupiter!

I suppose this micrometric eyepiece would be quite hard to use in the dark?

[Merlin66]

Quote: "I suppose this micrometric eyepiece would be quite hard to use in the dark? "

Not sure why you would think that? You'll need some red illumination to read the protractor scale, everything else is done by eye looking at the double double star image. By rotating the crystal and noting the "pattern" of the four images you can quickly and easily determine separation and position angle.

PM me and I can send a couple of user notes....