211221 - Sh2-184 "Pacman" nebula

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ASTRO:
     type=HII emission nebula
     mag=7.4
     const=Cassiopeia
     dist=9500 ly
     size=97 ly
IMAGE:
     location=EB Driveway
     moon=91% WnGb
     BrtlCls=5
     exposure=DSLR OSC; 37x420s (4.3h), ISO3200
     palette=SHO
EQUIPMENT:
     camera=Nikon D90 (mod)
     optics=ES102 w1.0x fltnr, F=714mm, f/7.0
     filter=Radian Triad QNB;
     mount=Celestron AVX
     guiding=Orion 60x240mm, ZWO ASi224MC
SOFTWARE:
     acquisition=Stellarium, APT, PHD2,
     processing=DSS, PhotoshopCC, LrC

The Pacman Nebula (also known as NGC 281, IC 11, and Sh2-184) is a bright emission nebula and part of an H-II region in the northern constellation of Cassiopeia and is part of the Milky Way's Perseus Spiral Arm. This 20×30 arcmin sized nebulosity is also associated with open cluster IC 1590, several Bok globules and the multiple star, B 1.  It collectively forms Sh2-184, spanning over a larger area of 40 arcmin.  A recent distance from measurements of radio emissions made during 2014 is estimated it lies appx 9200 ly from Earth.  NGC 281 is also known as the Pacman Nebula because of its resemblance to the video game character.  The nebula region is visible in amateur telescopes from dark sky locations.