Pacman Nebula NGC281
NGC 281 is a pretty bright HII emission nebula in Cassiopeia also known as the Pacman Nebula due to its resemblance to the video game character. The central star cluster is IC 1590 which is formed from hot, young blue supergiant stars of spectral class O and B . As an active HII region, the Pacman Nebula is what remains of an interstellar cloud of gas and dust in which star formation took place recently. The age of the stars in the cluster is only a few million years. The stars of the cluster, especially HD 5005 the brightest member, are the source of the powerful radiation that heats and ionises the remaining gas.
If you look near the centre of the Nebula, you can see where the stellar winds of these stars are creating a giant, darker bubble in the gas cloud around them. The denser parts of the cloud resist the erosion better, forming lumps called 'Bok globules'. Globules also absorb stellar winds, shielding the regions behind them. The result is a dense head and a thinner tail behind, with the head pointing towards the source of the stellar wind,
The cluster stars are sculpting numerous "tadpole" projections along the upper periphery of the visible nebula, a bit like Hubble's "Pillars of Creation" in the Eagle Nebula. To the left of centre is a large dust cloud, also eroded by stellar winds, that represents the Pacman's "mouth". The nebula lies 10,000 light-years from Earth.
Orion Optics UK AG16 Astrograph: SBIG 11000 CM: Titan Mount, Photoshop, Pixinsight
26 x 10 minutes (4hrs 2o mins) with IDAS D1 filter
Data capture : 22nd, 28th, 29th, 30th September 2014 under mixed skies!