Tackling the Cocoon

[scarp15]

IC 5146 is an emission / reflection nebula in Cygnus that invariably comes up as a topic of conversation at this time of year.

The Cocoon is a challenging object to observe that might often require repeated attempts and only under dark skies with good / very good transparency conditions.

Located due east of open cluster M39, initially detecting a long dark nebula Barnard 168. This feature is relatively straight forward to determine, then enabling the telescope to drift along to reach a small and forming open cluster. Embedded within this is a diffuse round glow, which is the Cocoon nebula.

Quite recently I gained an opportunity to venture to a dark site and attempt to observe this object. Growing accustomed and becoming reacquainted with searching for, then observing brighter and sometimes unsuccessfully fainter targets enabled my vision and perception to fully acclimatize. The best chance for detecting IC 5146 is with a H-beta filter. I set this up with a 31mm nagler and 14" dobsonian. Coupled onto a paracorr, this provided X59 mag and 5.84mm exit pupil with 1.38 degree field.

Detecting the Cocoon was one that required checking and rechecking. Locating the small forming cluster I could detect a subtle diffuse round glow. A gentle tap to the scope assisted, discerning that the image was neither dew on the mirror or filter nor star reflection. Perhaps having a companion around would have helped to verify this. Like many of these challenging objects, it is certainly one to return to and under excellent transparency, will become a little more apparent.

Are you therefore planning on attempting to observe the Cocoon or have you been successful? What have been your own experiences successful or otherwise and what requirements do you consider helpful and necessary?

 

[PeterW]

Yep, I think this was with my 80mm scope, swept across to it from the North America. Little ball of glow with a dark fringe, from a dark site last year. I would have thought this one would be easier, but I have not come across many reports, so maybe not. 

 

Cheers

 

peter

[cotterless45]

I had a bit of bright half circle in a 10" Dob. This however was from North Skye new Moon and deep dark skies. Finding targets is so very easy with a dark background granulated with stars,

Nick.

[jetstream]

The Cocoon is actually hard to see and underwhelming when seen, IMHO. I personally find the Dark neb that leads to it much more interesting. Even in VG skies it doesn't offer me much, its not on my goto list lol!

Congrats for nailing the Cocoon Iain!

[ollypenrice]

Yes, I found the dust lane easier than the bright nebula as well, which came as a surprise.

Olly

[scarp15]

Completely agree, it is a bit underwhelming to observe (not unlike other H-beta subject related targets) and yet - it perhaps belongs to that class of selective objects that make it quite discerning in as far as the desire to somehow capture it visually is concerned. Not unlike the Horse Head, it is quite well known and appealing when seen in images, so to gain a glimpse of this evocative object is in itself, at least a subjective reason to go and hunt the Cocoon - because its there, because it is elevated in a commanding position and because it is hard, challenging the observers vision / perception, equipment and sky quality / transparency. 

[PeterW]

Looking visually for nicely images objects I like CED214 and NGC 7822. A friend took a lovely shot, was great to find it and show him.... Imagers quite often don't know where in the sky things are.

cheers

peter

[scarp15]

Cheers Peter, so many intriguing emission nebula to discover, so few opportunities to get to explore.

[estwing]

well done sir!...not had a bash at this myself, but hats off to you for bagging this...PS The cone is my next must see!..clear skies Iain

[PeterW]

Fox fur is large and diffuse, come is another wee chappie like the nags head. Another one for me to bag... I prefer my nebulae to be on the large side!

Happy hunting 

peter

[PeterW]

Ok, it's clear, let's have a(other) go. follow "up through Texas" away from the Gulf of Mexico (of the North America), on past a diagonal line of brighter stars and there, just, is the cocoon..., thank you interstellarum. Not something i could get anyone exited about, but a smudge never the less.

cheers

peter

[Special K]

I've landed on the cluster for sure but not seen the cocoon within. It certainly is worth the effort to chalk it up and as mentioned the Dark Cigar is an added bonus for going to the trouble.  I've not had much luck really "seeing" dark nebs either, due to LP. 

It's Interstellarum all the way, Peter!

[PeterW]

Thanks. Will see if I can go "cigar hunting" tonight. I concur, dark nebs are something I have not had a lot of luck with. The number of times I have looked for the "triple cave/barnards E". Need to make a list of targets for my annual deep sky trip later in the autumn.

 

cheers

 

peter

[scarp15]

Which filter are you using Peter, UHC?

[PeterW]

Two hydrogen alpha filters (12+7nm) stacked. Tonight (streaky cloud, so probably not worth the effort) I'll switch to the 680nm long pass which is best for stars). I use light amplification which is sensitive to near IR, hence I can filter out most light pollution, useful for an urban observer.

Cheers

peter