Neptune Images
Neptune is an easy object to see in amateur scopes if you know where to look.  It is bright enough to be seen in a good pair of astronomical binoculars,  but you never see very much.  The small planetary disk is about 1/12-1/15 the size of Jupiter, so it is impossible to see any detail on the surface of the planet.   You probably need at least a 6" scope to easily notice that Neptune looks much different than a small blue-green star.   Neptune has a small set of rings, but these too are invisible in amateur scopes.  You can watch Neptune move among the stars from night to night.   The images here were all taken with my 8" LX200 and a MX-5C CCD.  With this size scope and a CCD camera, you can easily image the the largest moon Triton, which follows a circular orbit about Neptune.  At magnitude 13.5, Triton is about the same brightness as the planet Pluto, and can be seen with a 10" scope under good conditions.  The other moon, Nereid, is extremely dim at magnitude 18+.  It also follows a highly elliptical path with an orbital eccentricity of 0.5.   This sometimes places Nereid almost 10 Jupiter diameters from Neptune.  So it is very easy to loose Nereid among the background stars.  Needless to say.  Nereid is a very difficult object to see/image in amateur scopes.

 
 
Scope:  8" LX 200 SCT
MX - 5C CCD
This image of Neptune was taken on 3 Aug 99.  Neptune is the blue-green "star" in the upper center of the image.  Triton is between Neptune and the star marked with an arrow. 

 

Click here to download a PC DOS program (46K zipped file) to show the positions of the moons of Neptune.  This program is freeware.  Note:  I discovered an error in the original version.  If you downloaded this file before 20 Jun 2000, you need to download it again to get the revised version

 

 Focal Ratio:  f10 
Exposure:  8 sec for planet, 240 sec for Triton.
Scope:  8" LX 200 SCT
MX - 5C CCD & STAR 2000
Focal Ratio:  f10 
Exposure:  16 sec for planet, 300 sec for Triton.
Scope:  8" LX 200 SCT
MX - 5C CCD & STAR 2000
Focal Ratio:  f10 
Exposure:  5 sec for planet, 300 sec for Triton.
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