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Splitting Rigel

Space Hopper

By Space Hopper
in Observing - Discussion

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Space Hopper

Space Hopper

Posted
Posted

After being surprised to find that Rigel was a double ( after reading the interesting article in Decembers Astronomy Now) I decided to have a crack at it tonight.

I set up my 5" refractor, but its low altitude gave me problems....it was twinkling that much at high power, it reminded me of the 'beachball' on my AppleMac !!!

An hour later, things were a little better & my 5mm Vixen eyepiece ( 185x mag ) gave me a tantalising glimpse of what I thought was its 'B' component.

It's quite a tough one to split......Rigel is such a powerhouse of a primary !! Was this down to seeing, the stars low altitude or my scope I wonder ?

Has anyone else had any joy bagging Rigels 'little brother' ?

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alan potts

alan potts

Posted
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Stu,

I have managed Sirius but it is 11 degrees higher here so that makes a good deal of difference. I find Rigel very easy and hve split it with one of my 70mm Ed's when I had it on top of something ( APM I think ). The one that I can't split isw Antares.

Alan.

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Moonshane

Moonshane

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I find Rigel quite easy with either of my scopes (6" f11 or 16" f4 (especially if masked to 170mm F11). I am hoping to have a go at 42 Ori later which is apparently quite tricky. Delta Cygni is quite similar but not as bright a primary as Rigel and a little more colourful with a yellowish primary and brick red secondary - nice!

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John

John

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I find Rigel a fairly easy split with my 4" refractor if the seeing is at all decent. I've not managed Sirius B though, despite a number of attempts over the years with different equipment. It was split at the last SGL star party by one of our members (Lunator I think ?) using a Orion Optics 10" mak-cassegrain. A number of folks shared this but I missed it !

Eta Orionis is a nice challenge for a 4" scope. I believe the separation is around 1.6 arc seconds with mag 3.8 and 4.8 components. Needs quite a bit of power to get a clear split and good seeing conditions.

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Marki

Marki

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I first managed Rigel in my 125mm f9 achro quite recently - after a fair bit of trying. After the first time it seemed a lot easier... . Since then I've managed it in my 100mm f13 'frac and 100mm f10 'frac, although I need to wait for decent conditions (or at least relatively late so that it is higher in the sky). Sirius is always pretty low when I've been out recently, so I've not tried that really - don't really have much expectation of getting it from my backgarden. Gonna have a crack at 42 orionis again as soon as the conditions allow - these still elude me :). But loads of things to look at in Orion, and I easily get distracted by M42, so never get frustrated :grin:.

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  • 2 weeks later...
Mr Onions

Mr Onions

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Yes 100% sure split in 80mm APM/TMB f/6 with LOMO lens in USA desert.

Very good article on cloudynights.

Very reliable and experienced observers made it.

The very best scopes for double stars are long focus refractors.

My 60mm f/17.4 splits Izar eBootis so easily.

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Moonshane

Moonshane

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Yes 100% sure split in 80mm APM/TMB f/6 with LOMO lens in USA desert.

Very good article on cloudynights.

Very reliable and experienced observers made it.

The very best scopes for double stars are long focus refractors.

My 60mm f/17.4 splits Izar eBootis so easily.

Whilst I agree that a slow scope is better for doubles generally I think with things like Sirius B the scope is often irrelevant, it's the seeing/conditions and the experience/patience/persistence of the observer that matters most, all closely followed by exit pupil size (this being determined by the speed of the scope of course with a given eyepiece). Izar is a simple double to split and is routine with any scope I have used given the conditions being good enough and the star system high enough.

My most impressive double star observing is done with my large newt masked to 130mm. This creates a (almost) 7" f11 scope with no secondary obstruction and exit pupils below 1mm seem to work best and below 0.5mm seem to result in exceptionally round point stars with clear airy patterns.

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John

John

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I tried fitting an occulting bar to a 4mm ortho eyepiece last year to help with Sirius B. I still did not manage it using either a 6" refractor or a 6" mak-newtonian, both of which gave really tight airey disks.

I'll give it a go when my OO 12" F/5.3 newtonian is up and running. That has curved secondary supports, a 21% secondary obstruction and pretty good optics so may be able to crack it, if the conditions are right.

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