Neptune through a 5" APO?

[prova]

Just wondering would Neptune visable through a 5" (130mm) APO triplet?
If not, what is really needed to see it!?

[astroron (Ron)]

Yes, at mag 7.9 it is a bright enough target, but it could be mistaken for a star.
You would have use very high magnification and have good seeing to be sure of seeing it as a disc.

[Robh (Rob)]

Originally Posted by astroron

Yes, at mag 7.9 it is a bright enough target, but it could be mistaken for a star.
You would have use very high magnification and have good seeing to be sure of seeing it as a disc.

Agree entirely, Ron.
Uranus has an angular diameter of about 3.3-4 arcseconds and its disk is clearly visible at medium to high magnification. However, Neptune has an angular diameter of about 2.2-2.4 arcseconds. I find its disk much harder to resolve, even in a larger scope.

Regards, Rob