Taken from the same tour and location as the Wizard Nebula (link), the so-called Pacman Nebula, NGC 281 or Sh2 184, is a slightly larger nebula in the constellation of Cassiopeia. Similarly located within the Perseus arm of the Milky Way, it is ca. 9200 ly remote from Earth. Spanning an apparent distance of 40 arcminutes, careful processing has highlighted many fine structures around the mouth of the “Pacman”. As with the Wizard Nebula, the hydrogen-alpha emission is mapped to red, sulphur-II emission to yellow, with oxygen-III providing the magenta-blue highlights in the centre of the nebulosity.
Celestron RASA 11″
10Micron GM1000 HPS
SIGMA fp L (monochrome) / SIGMA fp L (colour)
H-alpha / S-II / O-III ultra-fast narrowband filters
ca. 3 hrs, ISO 1600, F2.2, 620mm