| Date 2015/10/08 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) | 0,96 '' of arc (1,92 '' of arc in total) |
| Image type | Ha (Ha-OIII-OIII) |
| Exhibition | Ha (11 x 10 'bin 2 × 2), OIII (11 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 nebula "The Bubble Nebula" |
| Constellation | Cassiopeia |
| Visual magnitude | 10 |
| Distance | 10 light years |
| Diameter | 11000 light years |
| Dimension seen from Earth | 15 x 8 arc minutes |
| NGC 7635 is aptly named “The Bubble Nebula”, as there is clearly a formation resembling a bubble at its center. The “bubble” is created by the Stellar Wind from the massive central star BD + 602522. It is a pale emission nebula. The Bubble Nebula is not visible in a small telescope because it is too pale. A telescope of at least 200 mm (8 inches) is needed to be able to distinguish the bubble faintly in a low light pollution environment. To photograph it, you need a long exposure time. Here I used an exposure time of almost 4 hours (3,67 hours) in 2 × 2 bin, equivalent to 14,68 hours in 1 × 1 bin. To counter the significant light pollution of my observation site (white area), I used the narrow band filter Ha (alpha hydrogen line) as a luminance image. It made it possible to bring out all the nuances of the nebula in this light spectrum while effectively cutting the light pollution of my observation site. |
| Richard Beauregard Sky Astro - CCD My impression "We cannot be alone in this gigantic universe" |