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Old 31-08-2018, 09:35 AM
Wavytone (Nick)

Wavytone is offline
Join Date: Jul 2008
Location: Killara, Sydney
Posts: 3,581
Hi Stephen good luck !

The second list is much harder than it looks.

A couple of nights ago I had a go at Rho Cap when it was near the zenith. The scope must be collimated perfectly, the seeing very good and enough magnification to cleanly show the airy disk and a couple of rings around a star like Acrux, for example.

Despite separation of 1.8 arcsec I had to push the magnification up past 300X - even had it at an insane 500X for a while - to be sure I could see it split cleanly, given the difference in magnitudes.

So these really are a supreme test of scope and eyeball.

I’ll add that some of these doubles have noticeable colour differences.
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