The Medusa Nebula aka Abell 21 is planetary nebula in Gemini; magnitude:10.19 ; size:12.4'x8.5' ; faint and large,OIII filter works well on this object ; the brightest area is crescent shaped ; best viewed in low power, some stars superimposed over nebula: I used a 21mm Ethos at 75x with a Lumicon OIII filter with my 14.5 Starstructure Dob f/4.3
The Medusa Nebula (Abell 21)
Posted 05 March 2020 - 10:02 PM
I recently hunted this down and was able to see it with my 12.5" Dob with an OIII filter in Bortle 4 skies.
It is really dim!
Posted 06 March 2020 - 12:19 AM
Fine sketch of the brightest horseshoe shaped part of the medusa head nebula (Abell 21).
Posted 06 March 2020 - 10:56 AM
Very good sketch of The Medusa Nebula (Abell 21) .