New Image: Abell 21, The Medusa Nebula

[Juno16]

Hi Everyone,

From Wikipedia:
The Medusa Nebula is a planetary nebula in the constellation of Gemini. It is also known as Abell 21 and Sharpless 2-274.
It was originally discovered in 1955 by University of California, Los Angeles astronomer George O. Abell, who classified it as an old planetary nebula.
Until the early 1970s, the nebula 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 large, its surface brightness is very low, with surface magnitudes of between +15.99 and +25 reported.
The central star of the planetary nebula is an PG 1159 star.



Don’t find many deep-space targets that were discovered my birth year!I
I spent a few hours imaging this target a few weeks or so while testing some modifications to my HEQ5 mount (DEC axis tune-up).
I had never seen or heard of this target before, but I needed a target in this part of the sky for testing.
After a week of poor weather, I tried processing the 2:56 that I had and didn’t expect too much since the nebula is extremely dim and my skies are quite messy (especially near the Celestial Equator).
I liked what I saw and anxiously waited for another opportunity to catch more data.

I finally got a break and collected another three hours (goes into the trees just after the meridian).
Nowhere near enough data for this cool-looking dim target, but no clear nights ahead before the moon creeps back in, so I settled for 6.9 hours of total integration.
Looking at the image after 2:56 vs. 6:56 integration, I saw a nice improvement in the definition of the serpentine filaments of glowing gas in the nebula “snakes”. Also, the wispy Ha below the
“snakes” is somewhat more visible.

Imaging information is on the Astrobin link, but basically:
Explore Scientific ED102/0.8FR/FF/ASI533MC/ HEQ5.
104 lights at 240 seconds with the Optolong L-Enhance filter 6.9 hours total).
Captured with N.I.N.A. and processed in Pixinsight and Photoshop CC.

My second planetary nebula!

Thanks you for looking and comments very welcome!

Jim

[Bigzmey]

Beautiful capture Jim! Love the colors, details and how sharp are your stars. Well done!

[JSBach1801]

Well shot and processed, Jim.

[messier 111]

very pretty, never seen that before, thx.

[Ylem]

Awesome image Jim!

[Juno16]

Beautiful capture Jim! Love the colors, details and how sharp are your stars. Well done!

Thanks a bunch my buddy!

Well shot and processed, Jim.

Thank you Lyle!

very pretty, never seen that before, thx.

Much appreciated Jean-Yves!
I hadn’t heard of the Medusa either.
Looks nice, but I don’t think that it gets imaged much.

Awesome image Jim!

Thank you for your always kind words Jeff!

[MariusD69]

Wonderful image! Very well done, Jim! I captured this nebula some time ago, with an old Atik314, but I want to try it again, at higher resolution (long list, short time).

[Graeme1858]

Excellent detail Jim.

As you say, we could wait for ages for another clear night! Glad you got another 3 hours.

This would be a good seven hours, SE to SW target for my location, I might give it a go and see how the Medway Towns light pollution and a neighbour's garden light that the cats and foxes set off affect my subs.

Graeme

[Juno16]

Wonderful image! Very well done, Jim! I captured this nebula some time ago, with an old Atik314, but I want to try it again, at higher resolution (long list, short time).

I certainly understand the list/time thing Marius!

This is not a commonly imaged target and is really dim, but I was happy with what I got for such a small integration time (needs much more).

I hope that you get the opportunity to catch some data on it. Is your old data able to be combined with new data, or would you rather collect new data only? Did you post your image here?

Thank you for your nice comments Marius!

[Juno16]

Excellent detail Jim.

As you say, we could wait for ages for another clear night! Glad you got another 3 hours.

This would be a good seven hours, SE to SW target for my location, I might give it a go and see how the Medway Towns light pollution and a neighbour's garden light that the cats and foxes set off affect my subs.

Graeme

I would like to see how someone else could do with this target and I hope that you get the opportunity to image it.
I saw on your sequence that it only rises to 52 degrees at your location. I was a bit luckier at 73 degrees, but I didn't get to take full advantage since it goes into the trees just after the meridian. The difference in brightness of the nebula in stretched lights from early in the evening to the meridian is significant.
I also see from your sequence that you have the wonderful advantage of shooting in mono. Really looking forward to your work!

Thank you Graeme!

[bobharmony]

You have done a really nice job with a tough small target, Jim. When I imaged this a couple of years back (or maybe it was last year) I didn't realize it's discovery shared our birth year.

[Juno16]

You have done a really nice job with a tough small target, Jim. When I imaged this a couple of years back (or maybe it was last year) I didn't realize it's discovery shared our birth year.

I read that and thought it was so cool.
Most astronomical discoveries were WAY before our time.
I’d never heard of the Medusa Nebula before, but found it on Skysafari and needed a target for testing for a few hours.
It looked interesting in the subs, so I caught more time a week or so later. Hopefully I can catch more time on it next year.

Thanks Bob!

[StarHugger]

Turned out nice Jim, almost looks tunnel like...

[Mac]

Great capture Jim. I might give it a try tonight, in between the clouds.

[Juno16]

Great capture Jim. I might give it a try tonight, in between the clouds.

I hope that you do get a chance to image the Medusa.
I would love to set up, but 90% chance of rain here.

The Medusa is really dim and needs a good bit of exposure time.

The L-Enhance did a fine job.

I believe that I have it upside down since the dim tendrils (at the bottom of my image) are supposed to be Medusa’s “snakes”.
Good luck! Can’t wait to see what you can do with it.

Thanks for your nice comments buddy.

[Mac]

I believe that I have it upside down since the dim tendrils (at the bottom of my image) are supposed to be Medusa’s “snakes”.

There is no upside down in space.

[Juno16]

I believe that I have it upside down since the dim tendrils (at the bottom of my image) are supposed to be Medusa’s “snakes”.

There is no upside down in space.

You are correct there!

[MariusD69]

Hi Jim! Sorry for delayed response. I posted the image in 2020, I did't remember if it was on this site, or into the previous one (astronomyforum). Now I want to capture new data. The old one has low quality (low resolution, small FOV, big halos around stars due to Baader OIII filter, no RGB for stars). But it has to wait. Now I'm working at Sh2-284 (I need 2 more nights for Ha and, maybe, 2-3 nights for SII). I'm waiting for clear skies.

[Juno16]

Hi Jim! Sorry for delayed response. I posted the image in 2020, I did't remember if it was on this site, or into the previous one (astronomyforum). Now I want to capture new data. The old one has low quality (low resolution, small FOV, big halos around stars due to Baader OIII filter, no RGB for stars). But it has to wait. Now I'm working at Sh2-284 (I need 2 more nights for Ha and, maybe, 2-3 nights for SII). I'm waiting for clear skies.

I found your image from 2020 Marius and it is really nice!
Very similar to mine, except yours has a tighter field of view.
I hope you do get a chance to image it soon. I would love to see your results.
Best of success on SH2 – 284!

[jthommes]

Beautiful image Jim! The color is great and the image depth is wonderful.