NGC 772 is a spiral galaxy in the constellation Aries. It is about 200,000 lightyears in diameter, double the size of the Milky Way and is about 130 million ly distant (cf. my last image, M31, at 2.5 Mly). That's what makes it quite difficult to image with a 10" telescope. The bright object almost directly to the south of the centre of the galaxy is NGC 770, a dwarf elliptical galaxy whose tidal forces on the larger galaxy have probably caused the emergence of the single elongated outer spiral arm. Halton Arp includes NGC 772 in his Atlas of Peculiar Galaxies as Arp 78.

Imaged with my usual setup. Luminance exposure (my longest ever) 5.67 hours in 400-second subs and R, G and B exposures 36 minutes in 200-second subs

Back to Thumbnails