| Date 2016/11/06 et 2016/11/07 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) | 1,57 '' of arc (3,14 '' of arc in total) for image Ha |
| Image type | Ha (Ha-OIII-OIII) |
| Exhibition | Ha (10 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 Medusa nebula" |
| Constellation | Gemini |
| Visual magnitude | 12 |
| Distance | 5000 light years |
| Diameter | 70 light years |
| Dimension seen from Earth | 60 x 30 arc minutes |
| IC443, also referred to as Sharpless 248 (Sh2-248), is a supernova remnant located in the constellation Gemini. It is called "The Medusa Nebula" for its great resemblance to the marine animal with the gelatinous body of our oceans. A supernova remnant represents the material that is ejected during the explosion of a supernova star. It is estimated that the explosion occurred 25000 to 30000 years ago. To observe it visually, in a site of low light pollution, it is necessary to use a telescope of 200 mm and more. The use of an OIII filter will help in its observation. The nebula then appears large and weak, accompanied by a few young stars. To resolve this image in my extreme light pollution site, I used the Ha narrowband filter (7nm) for object luminance, as the majority of the nebula's signal is emitted in this line. emission. To reproduce the color image, I used the Ha-OIII-OIII association which allows to simulate the natural colors of the nebula. |
| Richard Beauregard Sky Astro - CCD My impression "We cannot be alone in this gigantic universe" |