Medusa Nebula (Sh2-...
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Medusa Nebula (Sh2-274; Abell 21; Planetary Nebula PK205+14.1)

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The Medusa Nebula (Sh2-274; Abell 21; Planetary Nebula PK205+14.1) was named after the Gorgon Medusa, a hideous creature in Greek Mythology with snakes for hair.  It is a large planetary nebula that was thought to be a supernova remnant until the early 1970s and is about 1,500 light-years (ly) away in the constellation Gemini with a diameter of about 4 ly.  Because of its large size, its surface brightness is low making it a difficult object to find visually.

The central star of the Medusa Nebula is classified as a pre-degenerate star, or a PG 1159 star. As these stars degenerate and shed material, they become white dwarfs. In the annotated image, the crosshairs of the PK205+14.1 designation lie directly over the bluish, central star of this nebula.

The Medusa Nebula gets its name from the intertwining filaments of hydrogen gas seen easily in the top of the image and that resemble the Medusa’s snake-like hair. Below the bright upper portion of the image (the snakes), one can imagine the Medusa’s face, complete with a left eye glowing red, a space for a nose, and a mouth below that.  The stuff of nightmares…

Capture Date: 3/12/2024


Celestron EdgeHD 800 w/0.7x reducer (fL 1442mm; f/7) with Celestron OAG and ASI174mm mini guide camera

ASIAir Plus, ASI2600MC, ZWO AM5 mount, ZWO 5-position filter wheel

Antlia ALP-T 5nm Dual Narrowband Ha/OIII filter [20 x 300s = 1:40]
Luminance (UV/IR cut ASI2600MC) [20 x 60s = 0:20]
Total Exposure: 2:00

Processed with PixInsight and Adobe Photoshop.

This topic was modified 1 month ago 3 times by Greg Erianne

Terri Zittritsch
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Joined: 4 years ago
Posts: 327

Hi Greg, great image, colors and details.  I’ve been shooting this and may be done with it after getting a bit of RGB.   It isn’t the most beautiful object and even with the best scope, it doesn’t really have crisp details.   I see this in my own frames.    In any case, a great job capturing it.   You’ve got that Edge working well.  My 11” will be installed soon….  You may hear screaming all the way up there on route 2a when I can’t get it to guide well!!!  Haha.



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@terri Thanks, Terri!  Can't wait to see your image.  I really didn't have much time on this at all, and it was only shot with a OSC camera, but since I didn't have any idea when I'd get back to it I thought I'd post what I had.   I'm certain yours will be much better!

Ah, yes, getting the EdgeHD's to behave.  So many nights when I'm shooting with my HD8 I want to click my heels together and just keep repeating, "there's nothing like a refractor, there's nothing like a refractor, ..."   Doesn't work, though.  It's still my EdgeHD! 🤣  

Good luck with it...I'll be listening for tormented screams coming from up 'north'!


This post was modified 1 month ago by Greg Erianne

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