Splitting Izar

[Steve1976]

Is this meant to be quite a difficult double to split? I've tried on two nights now but can't seem to nail it. I'm 99% sure I'm looking at the right star!

[John]

What scope are you using ?.

I think the separation with Izar is around 3 arc seconds but the unequal brightness of the componants adds to the challenge. That said it's not too difficult with my 4" refractor and easy with the 6".

It needs reasonably high power to do it justice.

[NGC 1502]

Hi, Well I was viewing Izar last night, using my ETX 90. It's a tube only, on my alt az mount. It split quite easily at 170x. It was a hazy night, but I enjoyed an hour from 11 till midnight, looking at double stars. Also looked at the "double-double" a fine sight. Cheers, Ed.

[brianb]

It needs reasonably high power to do it justice.

And good seeing ... with the jet stream smearing stars out into a fuzzy blob (as it often does in the UK) you haven't a hope, whatever scope you're using.

With a fairly close, unequal double like Izar, accurate collimation is essential. With a Newtonian sometimes you can be unlucky and have the secondary superimposed on the diffraction spike caused by the spider, this will hide it for sure - try rotating the tube 30 degrees in its rings.