Struggling with visual - Cocoon and Wizard Nebulae.

[Ships and Stars]

Has anyone been able to observe either the Cocoon or Wizard nebula? I struggled to get much from them last night, even with a lot of aperture and a good H beta filter (Wizard apparently likes the OIII - will try that one next time).

Just returned with the big dob after some DSO visual before the moon got too high. Quite clear here tonight and definitely cold, had my Swedish insulated coveralls on and a balaclava, nice and toasty. Forecast was for -2C by mid evening. Set up scope by 7:45pm at my Bortle 4 spot near home, 21.55 SQM and little artificial LP. Didn't have time to drive to the Bortle 2 spot, unfortunately.

I'm still a novice, but my goal was visual on the Cocoon nebula. My first try using an Astronomik H beta filter on the 17.5mm Morpheus. I thought it would be a piece of cake with a 20" dob and the Milky Way clearly stretching across the sky...it wasn't.

Scope did a successful align and I slewed to M57 to check. It was within inner 1/3rd of EP. I punched in IC 5146 and went over to the dark cigar lane, so I was definitely in the neighbourhood.  After briefly studying AP pics of the Cocoon this afternoon, I think I had it narrowed down between two sets of stars, it should have been bang in the middle of the EP. There was at first a dark patch where the nebula should be, but no nebulosity. Thinking my alignment was off, I slewed around the cigar looking for something even remotely obvious. Nothing.

After a break looking at other targets, I returned to IC 5146. Using the SW Synscan controller, I slewed back and forth repeatedly on rate 3 to slowly pan across the area using averted vision and finally picked up a fleeting patch of apparent nebulosity, but I mean it was seriously faint! This sucker is going to need Bortle 2 and top seeing conditions  - or else I was, erm, looking in the wrong place. I think I was on the money however, and will call it a 'maybe'. Just to try, I swapped in the UHC and seemed to pick up an even larger area of nebulosity, but equally fleeting and faint. Hmmm....while I was in the area I had a brief look at M39, a nice star cluster.

Anyway, after that battle, I revisited the Western Veil and it was simply magnificent through the 21 Ethos and OIII. I scanned back and forth for awhile and soaked in the view. I definitely want to try the Veil with binoviewers, don't see why it wouldn't work, albeit at relatively high mag.

I then went over to the Blue Snowball, should have been an easy one, but I think my alignment was just enough off by this point to miss it, so I hunted for a bit. I know it's a small planetary nebula, but not convinced I found it in the 17.5mm,  so I switched to the 9mm Delite with UHC and still didn't conclusively identify it. Must investigate the sky atlas a bit more and use a 2x barlow next time. Seems there are some fairly bright stars around it, so I probably slewed past it but no obvious small planetary leapt out...

I then went to the Wizard Nebula, a very tricky one apparently for visual astro, and picked up another fleeing patch of apparent nebulosity using the Hb ,so the swapped in the UHC and encountered some fleeting 'wispy-ness', but will reluctantly call it another 'maybe'. In reality I should have used the OIII in the 21mm, but not sure the site was dark enough for a proper ID. I hear it's a hard one, or at least that's what I like to tell myself! 

The Crescent Nebula was an easy and enjoyable sight, but by this time the moon was above the horizon and a subtle glow quickly began to creep across the sky, so I called it a night and packed up...

PS - before my eyes were dark adapted, M57 clearly had a striking iridescent blue colour to it (no filter on the EP by the way) - this is the second time I have seen this in M57 from decent skies in the 20", (not seen this in the 8" newt as I recall). Not a maybe or 'sort of' - it was definitely a vivid though subtle blue, so I have found it is possible to see some colour in DSOs besides M42, I think the trick is not being dark adapted, but viewing under relatively dark conditions.

 

Edited November 19, 2019 by Ships and Stars
combine threads

[Ships and Stars]

Discussion moved to Observing - Deep Sky.

Thanks.

 

Edited November 19, 2019 by Ships and Stars
moved to different sub-forum

[scarp15]

Hi

Firstly could I suggest that this topic be moved to Observing Deep Sky.

IC-5146, is a reflection, emission nebula, although it is also referred to as the cluster that the nebula appears to merge within (the Cocoon is also known as Sh2-125). A subtle low contrast subject that is quite difficult as it is embedded in this rich star field. A H-beta filter does enhance contrast within the emission feature providing a small faint glow mixed in around one of the more prominent stars. 

Trawling through my notes, here is an account dating from 5/8/14 and using my 14" dob. " An attempt to locate the Cocoon, which I do believe I did! - in the correct location, first a hint of B168, Dark Cigar and at the head, the small rash that is IC-5146 an emerging open cluster and embedded in this a faint cloudy 'puff', H-beta filter observing is a challenge". A bit sketchy but not untypical of my note taking. Not sure which eyepiece I had been using but it would have been low power perhaps the 21E. SQM readings on the night were 21.35 mag, I think that it is one of those targets that is potentially attainable with a varied range of aperture, it is though quite a challenge, particularly following on from exploring Cygnus. @jetstream will have some input into this, as I know that he has committed time and attempts on this.

Whilst in the area, the Fetus Nebula NGC 7008 is a nicely formed subject to explore. Cannot provide any comment on the Wizard.

Attention will soon turn towards and focus minds on Orion.

 

[Ships and Stars]

Thanks Scarp! I should take some notes but often very time limited on observing. I'll refile this one under observing deep sky back home. I'd like to add an sqm-l meter to my arsenal. Many thanks.

[Stu]

I've merged these two together now so all the comments stay in one place.

@Ships and Stars if you would like a thread moved again, just give one of the mods online a nudge via pm to wake us up and we can do that for you, rather than starting a new one 👍👍

[Ships and Stars]

46 minutes ago, Stu said:

I've merged these two together now so all the comments stay in one place.

@Ships and Stars if you would like a thread moved again, just give one of the mods online a nudge via pm to wake us up and we can do that for you, rather than starting a new one 👍👍

Thanks Stu, wasn't sure how to go about that and felt too silly to ask, ha. Shall do some more research on the two DSOs and other similar ones before chasing them in the field with limited time.

9 hours ago, Ships and Stars said:

 

 

 

[Stu]

Good stuff. It's worth familiarising yourself with the concept of surface brightness, very important for understanding extended object visibility.

This site lists this measurement for many objects:

https://telescopius.com/deep-sky/object/7886/ring-nebula/m-57/planetary-nebula

This is a handy calculator for working out visibility based on aperture and sky brightness. I think it only works with aperture in inches.

https://www.bbastrodesigns.com/VisualDetectionCalculator.htm

[Ships and Stars]

Excellent Stu. This sounds perfect. I didn't realise the Wizard Nebula, for example, was something like 25' across and quite faint to boot.

I'll definitely study these links, many thanks!

[Stu]

8 hours ago, Ships and Stars said:

Excellent Stu. This sounds perfect. I didn't realise the Wizard Nebula, for example, was something like 25' across and quite faint to boot.

I'll definitely study these links, many thanks!

Yes, it's often the larger objects which have the lowest surface brightness as the brightness is spread over the larger area. They may seem bright just looking at their magnitude, but that's not the case when you consider surface brightness. Getting a handle on size is also very helpful to work out how best to frame the object and make sure you don't look through the middle of it with too small a field of view. You need to see the edges to perceive enough contrast to detect them.

Examples. M57 is very small and has relatively high surface brightness, the North America nebula very large and low surface brightness. At higher powers and a 0.5 degree field of view you can see M57, but look through the NAN. You need 3.5 or 4 degrees to see it properly. The small circle in the last image is the 0.5 degrees shown in the first two.

[Ships and Stars]

Ah right, this is helpful! NAN will be a bino challenge for the 12x70 binos from a really dark site I think. 4.6deg FOV with those. I definitely was looking through the Wizard the other night with the 17.5 Baader. I did get the sense the entire FOV was filled with very faint nebulosity. I'll use my 36mm aspheric and then perhaps the 21E, both with OIII for the Wizard. 

Lots to learn! Many thanks, the surface brightness vs size is a key aspect of chasing these and knowing which ones I can realistically see.

Cheers!

Edited November 20, 2019 by Ships and Stars

[Ships and Stars]

Stu - the BB Astro Designs calculator is brilliant - it gives min/max/ideal magnification and clearly tells me going from 21.5sqm to 21.9 will make a huge difference in seeing it vs not. 

My fav bit is where it shows what a scope half and double the aperture will show. I clearly need a 40" dob to make my life a lot easier! 👍 

I like this.

 

[Stu]

1 hour ago, Ships and Stars said:

Stu - the BB Astro Designs calculator is brilliant - it gives min/max/ideal magnification and clearly tells me going from 21.5sqm to 21.9 will make a huge difference in seeing it vs not. 

My fav bit is where it shows what a scope half and double the aperture will show. I clearly need a 40" dob to make my life a lot easier! 👍 

I like this.

 

Yes, it's very handy. Bear in mind also that surface brightness often varies across the object. M31 is a good example where the core is bright but the outer arms are very faint, the quoted SB will be somewhere in between. You see the core from almost any sky, but under a very dark sky with a widefield scope you can see it much larger as the spiral arms become visible.

The only problem with big dobs is that as they get larger, the focal length also goes up so the field of view gets smaller. You can get very fast, large dobs now, say 28" f2.7, but the exit pupils at low powers get huge and unusable eg a 31mm eyepiece will have an exit pupil of 11.4mm, so ideally you need to be a possum to make the most of that 🤣🤣

[Ships and Stars]

Yes my 55mm plossl was an excellent eyepiece but had something like a 13mm exit pupil, and that was f4! You can't have it all, as they say.

Good point too on the variable surface brightness.

I appreciate the information - this has been very helpful Stu.

 

[jetstream]

15 hours ago, Ships and Stars said:

Excellent Stu. This sounds perfect. I didn't realise the Wizard Nebula, for example, was something like 25' across and quite faint to boot.

I'll definitely study these links, many thanks!

Great report S&S, I have observed the Wizard in a different scopes- A few nights I followed nebulosity from the NAN all the way up into Cepheus, almost continuosly . The 200mm f3.8 newt is excellent for this but the bigger scopes will show these objects too. Its a good idea to start looking for shade edges with the bigger ones.

Most all my nebula observing these days involves the 20mm Lunt or 21E across the scopes (newts). Once you start seeing all this it starts to get hard to identify them, I think there might be some DSC that can help in this regard.

Your 20" under dark skies will show objects at the limit of most charts- and beyond. Try a tight, high transmission UHC from very dark skies...

Edited November 20, 2019 by jetstream

[Ships and Stars]

2 hours ago, jetstream said:

Great report S&S, I have observed the Wizard in a different scopes- A few nights I followed nebulosity from the NAN all the way up into Cepheus, almost continuosly . The 200mm f3.8 newt is excellent for this but the bigger scopes will show these objects too. Its a good idea to start looking for shade edges with the bigger ones.

Most all my nebula observing these days involves the 20mm Lunt or 21E across the scopes (newts). Once you start seeing all this it starts to get hard to identify them, I think there might be some DSC that can help in this regard.

Your 20" under dark skies will show objects at the limit of most charts- and beyond. Try a tight, high transmission UHC from very dark skies...

Thanks Gerry! I seem to pick some of the trickier ones but the app Stu posted really helps tame expectations. It's been difficult lately to get out at all, nevermind get to my Bortle 2 site (21.94 SQM, so quite good forthe faint stuff) due to family commitments.  I have to really plan ahead to get the most from any session these days... 

What high-transmission UHC do you recommend? I have the Astronomik UHC, OIII and Hb in 1.25", but only the OIII in 2". The 2" filters are a fair bit of dough! I ony recently picked up the Hb and UHC, really haven't used them much yet.

The Orion Ultrablock seems to get good reviews, though I've not tried it. 

 

Cheers!

[jetstream]

5 hours ago, Ships and Stars said:

The Orion Ultrablock seems to get good reviews, though I've not tried it. 

 

IMHO forget this filter, mine was a piece of junk that I chucked in the waste bin. The newest Astronomiks should be VG and I would seriously consider the new Televue filters rumored to be made by Astronomik to their specs. I have an older Lumicon UHC/OIII which are top notch but I would avoid the new ones. The Astrosystems dobs that I have include a filter slide which is fantastic and work with the Paracorr. Filter slides are well worth considering.

Its been raining/snowing/cloudy for a year here pretty much, I truly miss observing. You have some great skies available so take advantage of them as much as you can.

Eagerly waiting your Horse Head report with the 1.25" Astronomik Hb (same as mine) using a nice TV plossl! This will be a piece of cake for you if you keep scatter under control.

[Ships and Stars]

A filter slide would be excellent to easily check different views, a lot less faffing about in the dark with tiny, expensive bits of glass! I won't rush out to buy an ultrablock then, I went with Astronomik simply so I don't have to second guess my filter if I miss something.

Our weather has been unusually poor as well from some of the feedback I've been seeing, so hopefully we will all get a break soon. 

The Horse Head must be some rite of passage, but yes, that's a big one on my list! I've come close already from home believe it or not, but that was unusual seeing conditions and the business floodlights next door were off (that was nice!). 

I shall definitely report back if I locate the HH, thanks for the information as always!

PS - as always, any recommendations for filter slides?  I don't know a great deal about them, but I have seen some cheap ones online (something like £25) and some I believe that are for for AP only.

FLO sells this one: https://www.firstlightoptics.com/filter-wheels/manual-5-position-filter-wheel.html

Thanks again Gerry and Stu.

 

 

Edited November 21, 2019 by Ships and Stars

[jetstream]

One of the many reasons I chose the Astrosystems truss dobs is the filter slide. I looked around years ago for the slides with varying degrees of success. Some are no longer made, but checking around might reveal results.

Also, my latest purchase was a Paracorr II, I hemmed and hawed for a long time but it works very well and might be something for you down the road. Its works well enough I might go back to Delos for a great, low scatter, high contrast option that is easy to use in the PC. Astronomik make excellent filters.

Of course all this top stuff is nice but not needed to get excellent views IMHO... the SW 25 Super Plossl shows the HH for example,easily.

[Ships and Stars]

I was just thinking about the SW 25mm plossl and laughed, it probably would have been perfect for the horse head if contrasty enough. I sold it with my 130pds a few weeks ago. I'm fairly happy with my EP collection at the moment, but will go for a filter slide and another plossl in the 25mm range. However, I've a 66deg 20mm Williams Optics EP from my binoviewers, that might work!

SGL could host a cheapest ep and scope /Horse Head competition, with handicap ratings for different Bortle conditions! 

Clearly too much time on my hands at the moment, better get back to work...

Thanks Gerry!

[jetstream]

7 hours ago, Ships and Stars said:

SGL could host a cheapest ep and scope /Horse Head competition, with handicap ratings for different Bortle conditions! 

lol! I agree- my Vx10/Super 25 showed it and I'm positive a SW 200mm f6 dob would show it too, with the appropriate EP, maybe the vg 30mm Sterling plossl. A top Hb is needed though IMHO.

Your 20" will show the HH with no filter- my 15" does, with the UHC too.

[Ships and Stars]

I have a 200p on EQ5, that would be amazing if I could bag the HH from my 21.9 site!

I was really close here from home with the 20" but the LP is just a bit too much.

Desperate for some clear skies now but as I mention in my other post, not holding breath, forecast is Grim with a capital 'G'.

I did see a few stars last night through some clear patches, so hopefully the forecast is just wrong...

[jetstream]

2 hours ago, Ships and Stars said:

I have a 200p on EQ5, that would be amazing if I could bag the HH from my 21.9 site!

I was really close here from home with the 20" but the LP is just a bit too much.

Desperate for some clear skies now but as I mention in my other post, not holding breath, forecast is Grim with a capital 'G'.

I did see a few stars last night through some clear patches, so hopefully the forecast is just wrong...

What f ratio is the 200mm? Ive seen IC434 with my 200mm f3.8 but in this scope I'm looking for a tiny pimple of a HH notch. The extra FOV the shorter fl scopes give is not our friend for the HH IMHO, Alnitak is pretty bright.

There is no question in my mind the 200mm f6 newts will show it with the right combination- which means stray light control among other things.

[Ships and Stars]

4 minutes ago, jetstream said:

What f ratio is the 200mm? Ive seen IC434 with my 200mm f3.8 but in this scope I'm looking for a tiny pimple of a HH notch. The extra FOV the shorter fl scopes give is not our friend for the HH IMHO, Alnitak is pretty bright.

There is no question in my mind the 200mm f6 newts will show it with the right combination- which means stray light control among other things.

Hi Gerry, the 200p is f5 (I think) it could possibly be 1200mm though, but the OTA looks a bit too short. I'll have to measure it and make sure. It's the older blue SW 200p Newtonian on an equally old EQ5, but provides some decent views. Perhaps the potential is there to see the HH under the right conditions? I'll take it with me the next time I get a crack at my Bortle 2 site - as soon as all our flood warnings here pass! Maybe I picked the wrong season to really get into astronomy! Hopefully Dec-Feb will shape up.

[Stu]

37 minutes ago, Ships and Stars said:

Hi Gerry, the 200p is f5 (I think) it could possibly be 1200mm though, but the OTA looks a bit too short. I'll have to measure it and make sure. It's the older blue SW 200p Newtonian on an equally old EQ5, but provides some decent views. Perhaps the potential is there to see the HH under the right conditions? I'll take it with me the next time I get a crack at my Bortle 2 site - as soon as all our flood warnings here pass! Maybe I picked the wrong season to really get into astronomy! Hopefully Dec-Feb will shape up.

The 200P dob is f6, the one on the EQ5 which is the 200P-DS as sold now is f5, so I assume this one is too.

[John]

I've managed (just !) to see the Horsehead Nebula a couple of times from my back garden which is on the fringes of a large town. I used my 12 inch dob and the Astronomik H-Beta filter to catch it. The target took a fair amount of practice runs and preparation before I managed to actually see it for the first time. Probably one of the least spectacular targets that I've observed in terms of what you see but I still feel that it's well worth "the chase"

Here is the report I posted when I managed to see it, if it's of any interest:

https://stargazerslounge.com/topic/304416-barnard-33-the-horsehead-nebula-at-last/

Your 20 inch under dark scottish skies should be made for such challenges !