Saturday, 15 November 2014

The Outer Gas Giants

After a successful forecast of reasonable seeing conditions in the UK (i.e. low 300 mbar geostrophic wind) I spent an evening at the observatory trying to aim a telescope so as to focus Neptune, then Uranus on a 6mm CCD chip. Despite the new mount being excellent at tracking this took some time, and it wasn't helped by the mount insisting on doing a meridian flip just before starting imaging. The 9.25 inch SCT 'scope was cooled, Neptune showed a disk in the eyepiece, and high magnification was achieved with an extended 2x barlow, to reach about 6m focal length. The only non-optimal factor was the collimation being out, which was clearly seen during a later image of Gamma Andromedae. I explored a range of objects until the corrector plate dewed up too quickly.
So I managed to capture video of: Neptune at 3x, Uranus at 4x, close-ups on Cleomedes and Aristarchus/Vallis Schröteri (which were low down and shaky), and longer exposures of the core of M31 (not shown) and NGC 7662 - the "blue snowball" planetary nebula. It was a lot of fun trying this all out freezing on a patio in a dark field, alone with the entirety of space!