Open Cluster M48 (NGC 2548), type 'f', in Hydra

RA 08 : 13.8 (h:m); DEC -05 : 48 (deg:m); Distance 1.5 (kly); Visual Brightness 5.5 (mag); Apparent Dimension 54.0 (arc min)
M48 is a quite conspicuous object and should be a naked-eye object under good conditions. The smallest binocular, or telescopes, show a large group of about 50 stars brighter than mag 13, the total number being at least 80. The more concentrated core extends over about 30 arc minutes, while the outskirts reach out to about 54', corresponding to a linear diameter of 23 light years at its distance of 1,500 light years (given so by Mallas/Kreimer and Kenneth Glyn Jones, while the Sky Catalog 2000 has 2,000 light years).

Source and more: SEDS

February 6, 2008 21:22 - 21:48 UT.
Imaging: William Optics Zenithstar 80 ED II APO with Meade 3.3 Focal Reducer at f/3 [focal length 240 mm], ATK16IC camera, Astronomik LRGB filters.
Exposures: L 10x90s [1x1]; RGB 5x30s [2x2], unguided.