Jellyfish Nebula (IC 443) realistically - how big of scope is needed to see this object?

[Brandon Hamil]

I have never been able to see supernova remnant IC 443, the Jellyfish Nebula. This must be quite the challenging object at the eyepiece. I have tried with OIII filters as others have suggested, but no luck. I am guessing this requires pitch dark, prestine skies and a massive mirror? Would love for any one to chime in with any tips/tricks/comments. Thank you in advance, Brandon.

[Howard B]

Hi Brandon, I saw it a few times with my old 20-inch, using an OIII filter, on the same night I could see the dwarf galaxy, Leo I. My notes say IC 443 was invisible without the OIII filter but looked like a bit of the Veil Nebula when the OIII was used.

[Clear Skies]

With my 14", just over a year ago under not so dark, but very transparent skies, 110x / 45':

26mm Nagler type 5: Only the brighter NE part is visible. Without a filter a faint, lighter region can be discerned, elongated NW to SE.

26mm Nagler type 5, Lumicon OIII: Using this filter the nebula is slightly more patchy than it is with use of the UHC filter.

26mm Nagler type 5, Lumicon UHC: Using this filter the nebula is defined more clearly, a clear arc of irregular nebulosity, curving from the WNW towards the SSE where a flattened triangle of three mag. 9 and fainter stars is visible, pointing NNW. The NW part of the arc is the brightest, where clearly irregular structure is visible but it's not a bright as, for example, the brighter segments of the "Veil Nebula" in Cygnus. Where the nebula curves towards the SSE it faints abruptly.
The view is slightly better with use of the UHC filter than it is with the OIII filter. The fainter SW part of the nebula is not visible.

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[Raul Leon]

Hi Brandon, The best view that I have had with my 14.5 Starstructure Dob of ic 443 is wih a Lumicon OIII filter and my 22mm Panoptic. It is very dim and mostly with averted vision and good seeing is a must.

[Norman]

Hello folks,
brightest arc very easy with 12" and OIII (Astronomik) under alpin skies. Unfortunately i missed to try the opposite arc for my skychart only shows the brighter one...

CS
Norman

[cloudbuster]

Hi Brandon and all, with my 10" under SQM 21.4 and transparent sky I could see the brightest NE arc using a Nagler 26T5 and Lumicon OIII filter. Best with AV, but also directly. Some differences in brightness on the arc were suspected.

Regards, Martijn

[Uwe Glahn]

Hi Brandon,

I've logged around one dozen observation of IC 443 but most of them were pretty disappointing. Thumbs up to Norman and Martijn, who were able to catch the nebula with mid size aperture.

In my mind, even the brightest arc is a tough object, also in larger aperture. You need at least a good, but not a perfect sky. Important thing is to know where to look at. The arcs react very different on filter. While the NE arc has a strong [OIII] ratio, the fainter SW arc (yes, it is also visible) is mainly in H-alpha, so you have to use UHC or H?. Best is to start with the [OIII] filament in the NE.

To show what to look at, please go to well done narrowband pictures, which shows the different emissions. Walter Koprolin (https://astro.nightsky.at/Photo/SNR/IC443_Newton.php) does a stunning work on this.

What larger aperture can show, is pictured in the sketch down below.

sketch: 27", 172x, [OIII], NELM 6m5+, Seeing III
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home (http://www.deepsky-visuell.de/Zeichnungen/IC443.htm)

[j.gardavsky]

Hello all,

my logbook has just 2 entries on the Jellyfish, no thin shock front, just an extended glow:
3rd February 2014: 6" F/5 achro, 30x, H-Beta filter (12nm)
4th December 2019: 6" F/5 achro, 30x and 23x, H-Beta filter (12nm)
Nothing seen with the OIII 10nm and 5nm filters through the small aperture of 6".

My thanks go to Uwe for his amazing sketch of the shock front!

Clear skies,
Jiri

PS edit: From my observing notes, the visibility of IC 443 has been comparable to the visibility of the nearby IC 444 with the same equipment, and again no sure resolved structures.

[Bertrand Laville]

Hi All,

I have been fortunate to observe and see IC 443 both in a LX200/10" and a 25"Obsession.
Here are some more details: http://www.deepsky-drawings.com/ic-0443-t635/dsdlang/fr
And my best sketch, among several attempts

Clear sky
Bertrand

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[j.gardavsky]

Hello Bertrand,

a really great and detailed sketch of the whole Jellyfish!
Next time, I will take my 12nm OIII to give it another try.

Thank you so much for sharing,
Jiri

[kisspeter]

Hi Brandon!
I have only an old negative observation of IC 443. But it was a funny one. With my 4" Newtonian I drew the whole starfield (2.9?) from a slighly light-polluted site and I thought I could see something from the nebula. I didn't have any filters back then. A couple of days later we went to a good dark site and I could not see the nebula at all.

[j.gardavsky]

Hello all,

finally, I have tried the Jellyfish together with the nearby IC 444 on the 28th February, when I have started my 2021 observing season.
Binoculars 15x85 (BA8), filters: Baader visual 10nm OIII

Whereas the IC 444 has been fairly well visible, and I was able to resolve one lobe, the Jellyfish has been fainter and it has shown just a faint oval, not the shock front.
The observing conditions have allowed to see the Lambda Orionis Nebula with unaided eyes.

A report, also on the other nebulae, is here https://www.cloudynights.com/topic/759113-start-of-the-observing-season-2021-ic-443-and-444-ngc-2175-sh2-261-m42-sh2-275-ic-410-sim-147/

Clear skies,
Jiri

[Uwe Glahn]

I just checked out the visibility of IC 443 with small aperture and to my surprise - it works.

(I was observing under a NELM 6m5+ sky with my new widefield 4-inch binocular and 14x with a field of around 5°.)

IC 444 was only suspected with Hß filter, but to me not visible with [OIII].
In contrast to this, IC 443 doesn't show any brightening with Hß, not at the position of the brightest shock front to the NE, nor at the fainter shell to the SW.
The [OIII] turns the topic and the main shock front was clearly resolvable along (parallel and directly NE) a faint star chain, starting from a 9mag (HD 43582) star along three more 10mag stars to the NW. The glow was visible as a straight brightening with around 15'x5'. With 14x it is still very small but clearly distinguishable from the star chain.

[j.gardavsky]

Hello Uwe,

a very nice report!
I definitely must give to the shock wave another try, even if 85mm aperture are less than your 4".

Thank you for sharing,
JG