| Date: 2015/06/13 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 in parallel with the Orion Mini Guider |
| Auto Guidance Accuracy (RMS) | 1,67 '' of arc (3,34 '' 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 nebulae "The Veil nebulae" |
| Constellation | Swan |
| Visual magnitude | +5 |
| Distance | 1500 light years |
| Dimension seen from Earth | NGC6992: 60 x 8 arc minutes NGC6995: 12 x 12 arc minutes |
| NGC6992 is nicknamed the Veil or Lace Nebula. It is part of a vast cloud of gas and dust (referred to as the Swan Veil Nebulae) listed by several nebulae, including the NGC6995 nebula which is located to the left of NGC6992 in the image. NGC6992 and NGC6995 are not visible in a small telescope because they are very dim. To see them in a large diameter telescope (8'' or more), you need a sky with very little pollution from city lights. Also as they are very dark, they are difficult to photograph. It requires a long exposure time per photo and the integration of several images. Here, the use of the narrow band filters Ha and OIII have all their importance in this sky of significant light pollution (white zone). They make it possible to effectively block the light spectrum coming from light pollution while allowing more than 95% of the luminance of nebulae to pass. NGC6992 and NGC6995 represent the remains of several exploded supernovas. Remnants of supernovae are the final evolutionary state of a massive star (more than 6 times the mass of the Sun) that ends its existence with a huge explosion. After the explosion, only a rapidly expanding cloud of gas remains surrounding the star's residue. This gigantic gas cloud (which we see here only a part) is conducive to the formation of future planets. The stars which surround it go by gravity, appropriate these gases and dust. This dust will then orbit around these stars. Subsequently, this dust will assemble by gravity to form future planets. It is a superb anthill for the creation of planets. Perhaps, one of them will be conducive to the creation of life! |
| Richard Beauregard Sky Astro - CCD My impression "We cannot be alone in this gigantic universe" |