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View Full Version : Telescopes (little help?)



AK
2003-May-05, 10:41 PM
Ave...

I know a good deal about theoretical astronomy, but when it comes to field work I know virtually nothing because of limited experience.

Anyway, what size telescope (talking amateur equipment here) is needed to resolve Neptune as a disk? And can a scope of this size find Triton at all? I know it (Triton) has very high albedo, but as a relatively small object at such a distance...

Thanks.

Gsquare
2003-May-06, 02:14 AM
.... when it comes to field work I know virtually nothing because of limited experience.

Anyway, what size telescope (talking amateur equipment here) is needed to resolve Neptune as a disk? And can a scope of this size find Triton at all? I know it (Triton) has very high albedo, but as a relatively small object at such a distance...


Interesting question, AK.
Your going to need a 6 incher just to BEGIN resolving the disk (although a good 4 inch refractor may barely show it at 200 X) at opposition under good dark sky.

To really start to get any appreciable disk you really need 10 to 12 inches, especially if you want to start tracking retrograde motion of Triton which hangs around 13.5 mag.

Triton max. distance is ~ 14 Neptunian radii. Has a 5.9 day period and with such a high inclination you ought to be able to track continously without it being hidden behind Neptune, (I think). :wink:

What size is your scope? This may interest you: http://www.astronet.ru:8100/db/msg/1162684

G^2

AK
2003-May-07, 12:08 AM
Thanks for the response. The skies around here are pretty good... a lot of open spaces with little to no light pollution. I recently gave away my old small scope, so I'm in the market for a new one, which was the real reasoning behind my question. I'd like to get one capable of at least that kind of resolution, without putting myself farther into debt. That IR picture is very cool.

Re: Triton I was more worried about being able to resolve it at all rather than it being occulted by the planet. But I infer that if it's ~magnitude 13.5 then it should be visible in a 10-12" scope.