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Old 12-04-2016, 06:02 PM
scr4 scr4 is offline
Join Date: Aug 1999
Location: Alabama
Posts: 14,120
Originally Posted by Chronos View Post
Which still makes it about 1/300 degree (or 12 arcseconds) across. That's resolvable with a ground-based telescope, but only an extremely good one (atop Mauna Kea, the best observing site on the surface of the planet, the atmosphere imposes a limit of at best about 0.4 arcseconds). By eye? Not a chance.
If I did my math right, it's actually about 5 arcseconds. (VY Canis Majoris: 990 million km diameter, divided by 1.3 parsec, convert to arcsecond.)

And a decent amateur telescope should show it as a finite size disk. A good quality >4" refractor can resolve 1 arcsecond on a good day.

Last edited by scr4; 12-04-2016 at 06:02 PM.