| Date: 2016/08/08 Observation place My permanent observatory in Longueuil in white light pollution zone |
Technical
| Telescope | Orion 80ED refractor - Diameter 80mm, focal length 480mm, f / 6 |
| Mount | Celestron CGEM |
| Imaging camera | Atik 383 L + monochrome regulated at -20o Celsius |
| Autoguiding camera | ZWO ASI 120MM with one optical splitter |
| Auto Guidance Accuracy (RMS) | 0,87 '' of arc (1,74 '' of arc in total) |
| Image type | Ha (Ha-OIII-OIII) |
| Exhibition | Ha (10 x 10 'bin 2 × 2), OIII (10 x 10' Bin 2 × 2) |
| Image acquisition software | Maxim DL |
| Guidance software | PHD Guiding 2 |
| Pretreatment | Maxim DL |
| Treatment | Photoshop and PixInsight |
Object description
| Object type | Emission nebulae |
| Constellation | Cepheus |
| Visual magnitude | +10 |
| Distance | A few tens of light years |
| Dimension seen from Earth | 50 x 40 arc minutes |
| In the image shown, the Ced214 nebula is on the left and NGC7822 is on the right. I chose to photograph these two nebulae at the same time, considering that they are very close to each other. Also, I find that the framing produces a beautiful composition by presenting the weak nebulosities between them. For the description of the Ced214 nebula, see the nebula overview above. The two nebulae represent a complex of young stars at most only a few million years old (compare to the age of the universe which is 13,73 billion years old!). The radiation from these stars ionizes the surrounding gas, thus making it possible to see the two emission nebulae in the image presented. These nebulae are very difficult to see visually. You need a telescope with a focal aperture of 500 mm (20 inches) and more and a site without light pollution. Using an H-Beta filter will make them easier to observe. It should be noted that with the use of this filter, some observers have managed to see them with a smaller diameter. Given the difficulties of visual observation, interest in these two nebulae is concentrated among amateurs of astrophotography. To resolve this image in my extreme light pollution site, I used the Ha narrowband filter (7nm) for object luminance. The latter made it possible to almost entirely eliminate the light caused by light pollution while allowing the light signal of the two nebulae to pass to more than 95% (which is mostly in red tones). I also managed to bring out the beautiful nebulosities between the two nebulae (of magnitude over 15!), Which always amazes me given the extreme light pollution of the observation site (Longueuil, in the suburbs of Montreal !). |
| Richard Beauregard Sky Astro - CCD My impression "We cannot be alone in this gigantic universe" |