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Contains:  NGC 2395
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Abell21 HaLRGB, 


Abell21 HaLRGB
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Abell21 HaLRGB

Technical card

Imaging telescopes or lenses: Skywatcher ED80

Mounts: AZ-EQ6

Guiding telescopes or lenses: Orion thin OAG

Guiding cameras: QHYCCD QHY5

Focal reducers: Skywatcher .85x Focal Reducer & Corrector

Software: Main Sequence Software SGPro  ·  Pixinsight

Filters: Baader Ha 7nm 36mm  ·  Baader Blue 36 mm  ·  Baader Red 36 mm  ·  Baader Green 36 mm  ·  Baader Luminance 36 mm

Accessory: DIY Focus controllers

Dates:April 30, 2019

Baader Blue 36 mm: 31x300" bin 1x1
Baader Green 36 mm: 20x300" bin 1x1
Baader Luminance 36 mm: 35x600" bin 1x1
Baader Red 36 mm: 18x300" bin 1x1
Baader Ha 7nm 36mm: 28x900" bin 1x1

Integration: 18.6 hours

Avg. Moon age: 25.33 days

Avg. Moon phase: 18.68%

Basic astrometry details job: 3055166

RA center: 7h 29' 7"

DEC center: +13° 14' 42"

Pixel scale: 2.141 arcsec/pixel

Orientation: 355.515 degrees

Field radius: 1.059 degrees

Resolution: 2800x2200

Locations: Remote observatory, Kiev, Ukraine

Data source: Own remote observatory

Remote source: Non-commercial independent facility


The Medusa Nebula is a large planetary nebula in the constellation of Gemini on the Canis Minor border. It is also known as Abell 21 and Sharpless 2-274. It was originally discovered in 1955 by UCLA astronomer George O. Abell, who classified it as an old planetary nebula. The braided serpentine filaments of glowing gas suggests the serpent hair of Medusa found in ancient Greek mythology.

Until the early 1970s, the Medusa was thought to be a supernova remnant. With the computation of expansion velocities and the thermal character of the radio emission, Soviet astronomers in 1971 concluded that it was most likely a planetary nebula.

As the nebula is so big, its surface brightness is very low, with surface magnitudes of between +15.99 and +25 reported.
(c) Wikipedia



License: Attribution Creative Commons


  • Final
    Abell21 HaLRGB, 


  • Abell21 HaLRGB, 




Description: Pure Ha

Sky plot

Sky plot


Abell21 HaLRGB,