The Rosette nebula (NGC2237-9) surrounds the open cluster NGC2244 in Monoceros. According to Burnham´s Celestial Handbook it is located at a distance of about 2600 lightyears and has a diameter of about 55 lightyears.
© Philipp Salzgeber
| Film: | Kodak Multispeed / PJM-2 |
| Telescope/Lens: | Vixen 130mm (5,1″) f/5,5 Newton on a Super Polaris mount |
| Exposure: | 20 min. |
| Date: | 16 January 1999 |
| Image Processing: |
Removing of Vignetting (Radial Gradient), Removing of Uneven background due to light leak (linear Gradient) |
Comments:Guiding was done manually using a guidescope. This image should be regarded as a test/preliminary result, because many things were sub-optimal:
- Manual declination corrections because of lack of declination motor
- Film was 1 1/2 years old (stored uncooled).
- Polar alignment was done with polar alignment scope only, no drift alignment.
- I forgot the viewfinder magnifier and the F4 had run out of batteries, so I achieved no good focus.
- Some light-leaks in the film can, the resulting uneven film-fog could be removed only partially.
- Imaging with prime focus/guidescope for the first time.
- Guidescope deliverd bad images because of misalignment of focuser and lens cell.
- Main telescope was not collimated