I decided to give myself a challenge and try to shoot the dwarf planet Eris with my massive 0.13 meter refractor.
http://www.astropix.com/136199_Eris.html
Eris was shining at a faint magnitude 18.74, so this was not going to be an easy task, but it didn’t turn out to be as hard as I expected.
The first problem was that I wasn’t sure that I would be able to record Eris at all because it is so faint, and my local “dark-sky” observing site is not that dark, usually running at a Sky Quality Meter reading of about magnitude 20.5 to 20.8 at its darkest. I planned to deal with this in the normal way that we use to record faint objects… shoot a lot of exposures and stack them to improve the signal-to-noise ratio.
The second problem I thought I would have was that I didn’t know if I would be able to identify Eris even if I recorded it. The solution to turned out to be fairly simple – shoot Eris over the course of a couple of different nights and see if it moved.
It turned out that after stacking just a little less than an hour’s worth of exposures on the two nights, that Eris was fairly easy to pick out even though the sky background was pretty noisy.
Eris is very interesting because of the controversy its discovery caused and the subsequent demotion of Pluto to dwarf planet status.
Jerry
couple of nice little galaxies in there too, 
