Astro Photos

  1. The Pacman Nebula (NGC 281) in Cassiopeia

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The Pacman nebula…

was so named because of its resemblance to the video game character. But the nebula NGC 281 is an ionised interstellar gas cloud (HII region), actively forming stars, and lying 10,000 light years away in the Perseus arm of our Galaxy, the Milky Way. The false-colour image shows three emission lines – hydrogen (green), silicon-II (red), and oxygen-III (blue). The latter two elements were synthesised inside earlier generations of stars, spewed out into the interstellar medium, and are now being recycled into the next generation of stars. There is a multiple star system at the centre – the bright starlight helping to ionise the gas and causing it to glow. Also visible are small, dark ‘Bok globules’, which are concentrations of dusty gas, cocooning newly forming stars in this stellar nursery.

Image details

Taken between 31st October and 2nd November 2016, 3.5 hours total exposure with a 6 inch (150 mm, f/6.25) triplet apochromatic refractor and a CCD camera with 3 narrowband filters tuned to H-alpha (shown as Green), SII (Blue), and OIII (Red) emission lines.

Photo copyright © Geoff Cottrell 2016

2. The Andromeda spiral galaxy – our closest big  galaxy neighbour

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A one-hour exposure of the Andromeda galaxy M31 with its two dwarf companion galaxies, middle left and lower right, juxtaposed with a 1/100 second exposure of the Moon, to scale. M31 is 2.5 million light years away, heading in our direction (towards the Milky Way) at a speed of 400 million km per hour, and will merge with our Galaxy in about 4 billion years.

For these images, I used a 6 inch (150 mm, f/6.25) triplet apochromatic refractor and a CCD camera.

Photo copyright © Geoff Cottrell 2016

3. The Soul Nebula (IC1848) in Cassiopeia

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The Soul nebula is part of a giant star-forming gas cloud in the Milky Way. The area covered spans at least four full-Moons and, like the Orion nebula, is a highly active star forming region.  Fierce radiation and particle winds from the newly forming stars, seen clustered and clumped inside the nebula, is blasting a vast cavity in the cloud, sculpting fantastic shapes, and compressing the gas in the outer parts. This in turn is triggering a new wave of star formation in the periphery.

Image details

Taken between 7th and 28th November 2016, 4 hours total exposure with a 6 inch (150 mm, f/6.25) triplet apochromatic refractor and a CCD camera with 3 narrowband filters tuned to H-alpha (shown as Green), SII (Blue), and OIII (Red) emission lines.

Photo copyright © Geoff Cottrell 2016