|
Location/ Date: |
Eggersdorf, GER/ 21.+23.+25.+26.+27. March 2017 |
|
Telescope/ Lens |
10" f/4 ONTC Newton |
|
Mount: |
Celestron CGE GPS |
|
Camera: |
Atik 383L+ |
|
Exposure time: |
28x 1800" Astronomik Ha 6nm 23x 1200" Astronomik [OIII] 6nm 9x 300" Astronomik RGB each |
|
Total exposure |
23,9 hours |
| Description: | Abell 21, also known as the Medusa nebula lies in a distance of about 1500 light-years in the constellation of Gemini. This planetary nebula was created by a sun-like star which is in a late stage of development of a star of this size and mass. As a result of thermonuclear processes in the centre of the star the outer shell of the star has been pushed off about 6800 years ago. The remaining star is a white dwarf which is exiting the exausted gas hull to glow with its energy-rich UV radiation. The name of the nebula reminds of Medusa‘s head of the Greek mythology which was known to have a fibrous structure. |
50% Crop
50% Crop- invert version