Emission Nebula - Blog Posts

The Dolphin Head Nebula (Sh2-308, right) and Sh2-303 (left) // Jim Thommes

The Spaghetti Nebula, Sh2-240 // Wolfgang Bernhardt

The Dragon's Egg Nebula, NGC 6164 // Daniel Stern

This is the heart nebula (or at least as much of it as I can take with my setup without doing a mosaic) also known as IC 1805 or NGC 896. It is around 7 000 light years from us, in the constellation Cassiopeia. Despite its distance to us it still appears about twice as big as the moon in the sky, which speaks volumes when it comes to its actual size (about 200 light years in diameter).

This being an emission nebula its light mostly comes from gasses ionised by nearby stars.

This nebula also has an open cluster at it's center (a bit closer to us than the rest of the nebula), Melotte 15:

This cluster is bout 1,5 million years old which is very young for such a stellar object. It is composed a a few very heavy and bright stars and many fainter lighter stars.

The starless version :

(Image taken using a CarbonStar 150/600 newtonian telescope with a 0.95 coma corrector, ZWO ASI294 monochrome camera and Baader 6.5nm narrowband filter. 25x300s for the Ha filter, 26x300s for the SII filter and 26x300s for the OIII filter, total imaging time 6h 25min, stacking and processing done in PixInsight. Photo taken mid-January) Other versions with a different colour combinations (a bit less pleased of how they turned out).

If you want to see the nebula in its entirety, you can check out this NASA Astronomy picture of the day made by Adam Jensen.

Ok, so I finished the processing of my new photo of the Flaming Star Nebula (IC 405)

Image taken in SII and Ha with a few RGB images to have the correct star colours. This is technically an SHH combination image but with a narrowband normalisation and a lot of curve modifications (with and without colour masks) to get colours/contrast that I liked. I already had taken a photo of this nebula, but it was using mostly RGB data with a bit of Ha (and a lot less integration time). It did show the dust reflection way better, but I like the contrast we can see inside the nebula's gas on this one. Thanks to @shaythempronouns for suggesting the use of an SII filter to image this nebula. Starless version :

(Image taken using a CarbonStar 150/600 newtonian telescope with a 0.95 coma corrector, ZWO ASI294 monochrome camera ZWO LRGB filters and Baader 6.5nm narrowband filter. 5x120s image for each colour filter (RGB), 29x300s for the Ha filter and 33x300s for the SII filter, total imaging time 6h 35min, stacking and processing done in PixInsight. Photo taken mid-January)

Photo of the NGC 2237, the Rosette nebula and the star cluster inside it, NGC 2244.

The star cluster, which is estimated to be about 5 million years old, is responsible for the ionisation of the surrounding gas. The mass of the nebula is estimated to be about 10 000 times the mass of our sun, which is relatively massive for a diffuse nebula.

This image uses a SHO palette, I quite like the colours I manage to get, both as the normal and starless images.

I also tried using the Foraxx palette, I think it's a bit less interesting visually, but the dark dust structures seam a bit more visible.

(Image taken using a CarbonStar 150/600 newtonian telescope with a 0.95 coma corrector, ZWO ASI294 monochrome camera ZWO LRGB filters and Baader 6.5nm SHO filter. 5x120s image for each colour filter (RGB), 15x300s for the Ha filter 20x300s for the SII filter and 18x300s for the OIII filter, total imaging time 4h 25min, stacking and processing done in PixInsight.)

Picture of IC59 and IC63. This is a pair of nebula located near the star γ Cassiopeia, the big star at the bottom, which is responsible for making the nebula glow. Both nebula are composed of ionise hydrogen responsible for the red colour (especially on IC63) and colder dust/gas responsible for the blue colour (most visible on IC59). γ Cassiopeia can make taking photos of those nebula difficult due to the halos it produces, I did my best to limit its impact during processing, but there is still a faint blue halo around it. IC63 is also known as the Ghost of Cassiopeia due to its shape, it was discovered in 1893 by the German astronomer Max Wolf.

Image taken using a CarbonStar 150/600 newtonian telescope with a 0.95 coma corrector, ZWO ASI294 monochrome camera. 12x300s image for each filter (LRGBHa), total imaging time 5h, stacking and processing done in PixInsight. Details of both objects: IC63

IC59