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Technical card

Resolution: 2728x2180

Dates: Feb. 18, 2014Feb. 19, 2014Feb. 20, 2014

Baader Ha: 7x1200" -10C bin 1x1
Baader OIII: 14x1200" -10C bin 1x1
Baader SII: 15x1200" bin 1x1

Integration: 12.0 hours

Darks: ~25

Flats: ~20

Bias: ~50

Avg. Moon age: 18.47 days

Avg. Moon phase: 84.75% job: 191217

RA center: 112.231 degrees

DEC center: 13.276 degrees

Orientation: -96.008 degrees

Field radius: 0.596 degrees

Locations: San Jose, CA, San Jose, California, United States


The Medusa Nebula (or Abell 21) is a planetary nebula in a distance of 1,500 lightyears in the constellation Gemini. It was discovered fairly recently (1955) and it was first thought to be a supernova remnant. It has its name from the braided serpentine filaments of glowing gas which look like the serpent hair of the Medusa (from the Greek Mythology).



Mark Striebeck


Sky plot

Sky plot


Medusa Nebula, Mark Striebeck