criterion connection


Dumbbell Nebula by homcavobservatory
Via Flickr:
The Dumbbell Nebula (Messier 27) - is a ‘planetary nebula’ (i.e. a star in the process of dying) lying approximately 1350 light-years from Earth and spanning about 3 light-years in diameter, One of the larger and brighter planetary nebulae, it can be found in the constellation of Vulpecula. The first planetary nebula ever discovered (by Charles Messier in 1764), the central star is the largest white dwarf known and among those with the highest surface temperature (i.e. 85,000 K (as opposd to 5,778 K for our Sun)). Image Details: Taken by Jay Edwards at the HomCav Observatory using a (1970) 8-inch, f/7 Criterion reflector, connected to a Celestron coma corrector and Canon 700D DSLR; riding on a Losmandy G-11 dual-axis drive mount autoguided using an Orion Starshoot thru an 80 MM Celestron short-tube refractor, controlled by PhD 2.0. This image is our first test using this autoguided system and has been resized down here to HD resolution and the bit depth lowered from 16 to 8 bits per channel to reduce the file size.