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NEBULA - IC1805 Heart nebula

A random, 120s shot got me the below surprise. Framing is almost good.
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NEBULA - NGC281 Pacman nebula

The HII region is pictured here as it was 9500 years ago, when on earth Sahara was wet and fertile.

This is a single, 2minutes shot at ISO 1600. A satellite is visible as well.
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10/13/15
2 Photos - View album

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NEBULA - NGC6888 Crescent Nebula

This is a really cool nebula: the  Wolf-Rayet star WR 136 (HD 192163) - the one you see within the crescent - became a red giant somewhere around 400k years ago. It then ejected its outer layer of gas, which we see here shining at very high temperatures.

Now the oddity is - and this is the cool part - that this slow-moving gas is not excited by the star's UV radiation as is often the case, but by very fast-moving stellar wind, which has now caught up with the gas and is heating it to X-ray emitting temperatures.

So, to put it very scientifically, the faster, inner bubble has caught up with the slower, outer bubble and they now radiate in Ha as shown below. Also visible - through the noise - are faint extensions of IC1318, the nebula in Cygnus surrounding Sadr, and the open clusters IC1311 and NGC6874.

About 15 minutes total exposure, one minute shots at ISO800 with a modded 7D - Ha 6 nm, through a 60mm refractor at f/6.2, on a EQ6.
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NGC6888 - Crescent nebula
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NEBULA - IC1318 Butterfly Nebula

Each wing of the butterfly bears the romantic name of "IC 1318 B" and "IC 1318 C", while the dark band that makes the body is known as the "LDN 889 dust line" - 20ly thick. The bright Sadr, the middle star in the Cygnus cross, is seven times closer to us and is not associated with the nebula, which lies some 5000y away.

This is an active HII region excited by a star which is not optically visible, being hidden by the great cloud of dust that divides the Milky way. 

Little over 40 minutes of exposure made up of 1 minute frames at ISO 1600, Ha 6nm filter on a modded 7D through a 60mm f/6.2 refractor. This is a stack of the red channel only - 45 darks subtracted.
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2015-06-28
2 Photos - View album

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NEBULA - M57 Lyra

This picture shows the "planetary" nebula in Lyra as it was 2300 years ago. Now the funny thing is - I was looking for stuff that happened on Earth around that time and found that the oldest stringed instrument is dated 2300 years ago and it is, of all things, a Lyra. So there you go. 

It's a nicely coloured ring of gas made of the gas expelled by a red giant (wouldn't an exploding star create a sphere of gas rather than a ring?) which is now a white dwarf slightly larger than our Sun, but much hotter. Light needs one year to travel across it and its apparent size is about one degree.

Ubergeeks will be glad to know that in the same constellation (but closer to Vega) is found the "double-double" epsilon lyrae.
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M57 - Lyra
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NEBULA - NGC 7000 North America Nebula

Six exposures of 2 minutes each at ISO 1600 - 7Dmod and 60mm refractor on EQ6.

Heavy light pollution - sodium and mercury lighting from city nearby (pop. 300k).
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NEBULA - M8 Lagoon Nebula / M20 Trifid Nebula

Mars was low on the horizon at the end of October and I thought I would maybe catch that comet that swept by. Well, this is what I got, pointing the lens without really aiming.
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2014-11-01
2 Photos - View album

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NEBULA - NGC 6888 Crescent Nebula

A time-lapse over half a million years - in ultra slow-motion.

When the star WR 136 became a red giant some 400 000 years ago, it shed its outer layers propelling a slow-moving, expanding bubble into space. The high-velocity stellar wind that the star now radiates caught up with the bubble to create the Crescent Nebula.
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2014-10-27
3 Photos - View album

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PROCESSING - Red channel extraction for Ha

The same set of images were processed much the same way to give very different results. The better picture is a stack of the data in the red channel only, whereas in the noisier insert all three channels were kept.

The picture is still noisy, but the improvement is clear.  
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NEBULA - M42 Orion Nebula

Half an hour exposure (120s / frame) through a 6nm Ha filter. 
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