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A trio of double stars

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I went out this morning (1 Dec) at 6:30am and the sky was clear. The Moon was still up and there were wisps of high cloud so I decided it was going to be bright double stars only.

I pointed at Castor first and was greeted by a pair of 'eyes' at 150x. I like this double, because its so easy to find and looks nice at almost any magnification. The separation is now over 5 arcseconds and going to keep increasing for the next couple of decades.

Then it was Algieba in Leo, being almost directly south and high in the sky. This pair was a bit tighter at 4.7 and looked orange-yellow. 

The seeing was poor but at 150x I was happy and decided to attempt something more challenging. Arcturus was very prominent in the east so I tried  Izar (Epsilon Bootes).

This is where it got harder, at 150x I had trouble splitting at first. I think  being lower in the sky the seeing was worse and the star was smearing.

I waited a several minutes and eventually there were moments of stillness when I spotted the close blue companion :) Just to make sure I switched to 260x. It was blurry, not a pretty sight but I could clearly see it most of the time. This pair is closer, at just 2.7 arcseconds separation.

Normally Izar should not be difficult for my scope (180mm Skymax Mak) but it just goes to show how important the seeing is for  close doubles. 

I'm very pleased to observe something at last after all this cloud :)

Thanks for reading and clear skies!



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Good that you got some viewing in Nikolay - the 180 Mak is good for doubles, I imagine.  I have found my 8" SCT is not so useful for that purpose, giving mushy star images at higher mags.

Fracs are best, but are limited of course by smaller apertures.  Anyway, next time it's clear, I plan to get the 5" long focus frac out and try for some doubles at just over 1soa of separation.


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The 180 Mak deserves its reputation for doubles and planetary views, but no scope can beat the weather and poor seeing!

Last week, I had one good night where the E and F stars were visible in the Trapezium, several 1 arcsec pairs easily split in Orion, and even Sirius just about starting to split as it rose in the sky, but tiredness set in at that point. Good nights are few and far between!


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