| Date 2020/07/18 et 2020/08/13 Observation place My permanent observatory in Longueuil in white light pollution zone |
Technical
| Telescope | Celestron Edge HD - Diameter 203mm (8``), focal length 2032mm, f / 10 |
| Focal reducer | f / 6.3 (63%) |
| 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) | July 18: 1,12 '' of arc RMS (2,24 '' of arc in total) August 13: 1,43 '' of arc RMS (2,86 '' of arc total) |
| Image type | Hubble Palette: Ha (SII-Ha-OIII) |
| Exhibition | Ha (10 x 10 'bin 2 × 2), OIII (9 x 10' Bin 2 × 2) and SII (10 x 10 'Bin 2 × 2) |
| Image acquisition software | Maxim DL |
| Guidance software | PHD Guiding 2 |
| Pretreatment | Maxim DL |
| Treatment | Photoshop and PixInsight |
| Specific treatment | Hubble Palette |
Object description
| Object type | Emission nebula |
| Constellation | Swan |
| Visual magnitude | unknown |
| Distance | 5670 light years |
| Diameter | 24,7 light years |
| Dimension seen from Earth | 9 x 7 arc minutes |
| Nebula Sh2-112 is a bright emission nebula in the constellation Cygnus. It is located 5670 light years from Earth. Its diameter is 24,7 light years. It is illuminated in its center by the bright star BD + 45 3216, which makes it an emission nebula. The star is about 30 times the size of the Sun! The nebula is in an area dominated by the Milky Way. It is thus surrounded by the weak nebulosities thereof. In my image, we can clearly see these weak nebulosities around the nebula. Sh2-112 is not a particularly popular imaging target by amateur astrophotographers. However, she is very beautiful to image, as my image shows. The nebula is dominated by the H-Alpha signal. It also responds very well to OIII and SII signal, making it a very good candidate for narrowband imaging. So I took the opportunity to image it in a Hubble palette (SII-Ha-OIII). As the dominant radiation is in Ha, I used the image produced with this filter as the luminance image. In addition, imaging in narrow bands is very effective in combating the significant light pollution of my observation site which is in the white zone. |
| Richard Beauregard Sky Astro - CCD My impression: “We cannot be alone in this gigantic universe.” |