Neptune

[Darren B]

Last night went out observing with my 80mm refractor. The sky was a bit hazy and the atmosphere was very steady. I could easily see Jupiter. I printed of a star map from Stellarium to help me locate Neptune. I think I could see it in a pair of binoculars and if the Stellarium progam was correct I could easily see it in my telescope at 20x. I only took a few eyepieces out and the maximum magnification I could reach was 111x. As I went for higher power, Neptune was still star like. I could see a hint of colour (turquoise), but could not tell if it was Neptune or a star. What would I expect to see Neptune as in a 80mm scope at x111?

[George Jones]

Neptune's disk becomes apparent somewhere between x100 and x200, so x111 might be a bit small to notice this. With my 8'' (200 mm), I definitely can discern a disk at x254, and I think I can at x156.

Sounds like you saw Neptune.

[Darren B]

Thanks, I do have higher power eyepieces, but they're no good when left at home.

[Doc]

I need at least x200 in my 16" dob to resolve Neptune to a disk. But it is a nice turquise shade of blue so I would sy you saw it.

[Darren B]

Thanks, weather permitting I'll try again this weekend

[John]

I could just about discern Neptune's disk with my 102mm refractor at 186x. It's very small of course only 2.6 arc seconds in diameter - it's challenging for some smaller scopes to split double stars with that separation so it's no wonder that larger apertures are lots of power are needed to make the disk distinct !.

John

[mike.brightmore]

You might like to have a go at Uranus - it is easier to see it as a disc. Also quite a bit higher than Neptune.