Object: Constellation: Coordinates: Size: Brightness:
NGC 246 Cet 00h47m / -1152' 4' x 3.5' 10.9mag

The planetary nebula NGC 246 ("Skull nebula", "Pac-Man nebula") in the constellation Cetus on December 5 / 6, 2015. The expanding emission nebula ejected from a red giant star at the end of its life is 2000 light-years from Earth and was discovered by Friedrich William Herschel in 1785 (source: Wikipedia).

Twenty-one exposures of approximately 3 minutes at ISO 800 with no dark frame subtraction were stacked with Deep Sky Stacker (resulting in a 1 h 10 min exposure) and further processed in Photoshop.
Equipment: Canon EOS 450D Baader modified camera, TeleVue Paracorr Type II coma corrector, 16" f/4.5 "Ninja" dobsonian telescope riding on a dual-axis Tom Osypowski equatorial platform, Lacerta MGEN autoguider, Lacerta off axis system (field of view comparison: image of the moon with the same equipment).

Search chart for NGC 246. Map © 2016 "The Mag-7 Star Atlas Project", www.siaris.net. Map is modified. The map can be downloaded here .