M35, on the right, is relatively nearby at 2800 light years distant, relatively young at 150 million years old, and relatively diffuse, with about 2500 stars spread out over a volume 30 light years across. An older and more compact open cluster, NGC 2158, on the left. NGC 2158 is four times more distant than M35, over 10 times older, and much more compact with many more stars in roughly the same volume of space. NGC 2158’s bright blue stars have self-destructed, leaving cluster light to be dominated by older and yellower stars. Both clusters are seen toward the constellation of Gemini.

Imaging telescopes or lenses: Sky-Watcher 200/1000 Black Diamond
Imaging cameras: Canon EOS 450D
Mounts: CGEM
Guiding cameras: Lunatico Astronomia QHY5-II
Software: PHD Guiding, Incanus APT – Astro Photography Tool, PixInsight Core 1.8
Dates: Dec. 27, 2013
Locations: Albox
Frames: 24×300″ ISO800 bin 1×1
Integration: 2.0 hours
Darks: ~22
Bias: ~150
Author: Jose Fco. Del Aguila
AstroPhotography of the day by SPONLI 09 May 2014