The dark, the light and the challenge

[Littleguy80]

My third dark site trip of the week and I was feeling in good shape. I'd turned down clear skies Saturday for an early night. I arrived onsite nice and early giving me time to get everything set up, aligned, collimated and cooled before darkness arrived. A quick look at Jupiter and Saturn confirmed everything was ready for a night of nebulae hunting. Unlike my previous dark site visits this week, I'd had time to prepare for my session. Armed with a list of targets, images, sketches, star charts, as well as some challenges from Gerry @jetstream, I began the session in Sagittarius. I started with the Lagoon, M8, which had created quite an impression in my previous session. A quick filter battle between the Lumicon OIII and Astronomic UHC lead to a swift victory to the Lumicon. Once again the curving nebulosity creating a dark lane through the centre. I believe I also picked up the hour glass nebula which sits within the thicker section of nebulosity in the Lagoon. The Red Spider Nebula, NGC6537, was a new target for me. A lovely little planetary nebula not far from the Lagoon. I made use of the OIII on M16 and M17 before removing it to observe M24. The sky was dark enough now to enjoy the dark nebula, B92 and B93 in the star cloud. The Wild Ducks, M11, made a wonderful starting point for another new target. NGC6712, according to Interstellarum, it is known as the Weird Globular. I increased power and tried an OIII as suggested by Instellarum to try and pick out the dark lane within it but was unsuccessful. It's not unusual for details to go unobserved on the first observation so I wasn't too disheartened.

It was now time for Gerry's challenges! The first challenge was to see the Lagoon naked eye. I got M8 back in the eyepiece and used the Telrad to see whereabouts I should be looking. Sure enough a faint glow within the Milky Way could be seen. Success on the first challenge meant I was in with a chance of succeeding with challenge two. Gerry had provided a sketch by Mel Bartels of the Veil. Just above the Eastern section is a small detached section of nebulosity. I'd inverted the colours on the sketch and had it with me as a guide. On the sketch are two stars, HD199374 and HD199358 which are roughly in line with target nebulosity. I used these as a guide for my observations. The Lumicon OIII was screwed back in and the hunt began. It's surprising how much further the Eastern Veil extends when you start to look for the fainter parts. I experimented a bit exit pupil and decided that a larger exit pupil with the ES82 30mm worked best for me. Slowly but surely, I started to get glimpses of the challenge nebula. After about 20 mins, I felt quite confident in the observation. Now was the right time to go even fainter. SH2-91, the Little Veil, is something I've been inspired to try for by Gerry and Iain @scarp15. I'd spent a lot of time studying images of this to give me the best chance of seeing it. I started by centring on Phi Cygni/12 Cyg. The same large exit pupil and Lumicon OIII were employed to search this out. What I observed was a faint line of disturbance running above 12 Cyg. It had an almost translucent appearance right on the edge of what I could see with averted version. Had I not known that SH2-91 was supposed to be there I would probably have dismissed it. However, repeatedly moving along the line of disturbance showed it to be something that was actually there and not some other artefact. It feels odd to call it an observation but I guess this is normal for something so faint! I went back to the Eastern Veil and found observing the challenge nebula even easier. My dark adaption seemed to have gone up a notch from the search for SH2-91. Perhaps transparency had improved over that time too. I was super happy to have pushed myself to the edge of what I could see.

A brief viewing of the Crescent nebula before I joined the "Blue Flash Challenge". One of my fellow observers had been challenge to see NGC6905 in his frac. I pulled this lovely planetary nebula up in the dob. I then helped find it in the frac too. It was faint in the frac compared to the dob but most definitely there. A nice streak of nebulosity. I went back to Cygnus and the North American Nebula. The Pelican was showing well. Dark nebula were on my mind once again. B352 came quite easily but B353 took a bit more effort but was also observed. Transparency seemed to be dipping a bit now though. I dropped back down to Sagittarius and the Little Gem planetary nebula. Rather than increasing power on the little planetary, I went in search of Barnard's galaxy, NGC 6822. I'm not sure if it's just low surface brightness or that it's positioned quite low. Through experimenting with eyepieces, I was able to detect the faint glow of the galaxy. Another challenging target in the bag. A few more galaxies followed, Fireworks galaxy, NGC 891, NGC 7331 and a failed attempt at Stephan's quintet.

My final challenge of the session was a comet. C/2018 W2 (Africano) is listed at mag 11.4. It took some slow scanning but the diffuse glow, that signified the comet, was seen in the APM HDC 20mm. I'm looking forward to seeing this brighten over the coming weeks. Things were getting damp so a light hearted tour of M31, M32, M110, M45 and NGC404 finished up the 4 hour session. What a fantastic week of astronomy it's been!

[Stu]

Awesome stuff Neil, a really good report with some excellent observations. A cracking week as you say!

[scarp15]

I was looking forward to this next report Neil, that is quite a wholesome session to complete a productive observing period. Great that you were able to explore the Sagittarius region and to provide descriptive informed content for each region and subject. The challenges, well what can I say, that 10" dob, your observational skills, patience determination are paying off. The way you have described approaching Sh2-91 implies that you have registered this and if you gain any more opportunities this season, next season, in similar transparency conditions, that faint line of disturbance could extend a little. Anyhow really good read. I ought print out a copy of Mel Bartels Veil sketch to.

[Littleguy80]

1 hour ago, scarp15 said:

I was looking forward to this next report Neil, that is quite a wholesome session to complete a productive observing period. Great that you were able to explore the Sagittarius region and to provide descriptive informed content for each region and subject. The challenges, well what can I say, that 10" dob, your observational skills, patience determination are paying off. The way you have described approaching Sh2-91 implies that you have registered this and if you gain any more opportunities this season, next season, in similar transparency conditions, that faint line of disturbance could extend a little. Anyhow really good read. I ought print out a copy of Mel Bartels Veil sketch to.

Thanks Iain. Glad you enjoyed. I think familiarity is playing a part too. I’ve been using the dob with my widefield eyepieces for well over a year now. I know what to expect when I look through the eyepiece. Spotting things that are out of the normal, like the disturbance in the area of SH2-91, becomes a little easier. Three dark site trips in a week really helps to attune the eyes to observing too. Practise makes perfect as they say  

[jetstream]

Congrats Neil!

SH2-91 is not an easy target, ghostly in appearance and a worthy target for any scope. Did you see anything else in the area? there is another, tougher section that is visible

2 hours ago, Littleguy80 said:

My dark adaption seemed to have gone up a notch from the search for SH2-91.

It will for sure, but...

2 hours ago, Littleguy80 said:

a failed attempt at Stephan's quintet.

this is not surprising actually. If your like me then after concentrating on viewing very faint nebula my galaxy abilities are lacking. I noted this over and over and now when observing galaxies they will be the primary targets for the night- at the end of a session I might sky cruise nebula though.

Stephans Quintet is easier in a 10" than SH2-91 for me- I can get 3 very faint overlapping cores with the 10" and an ortho for best views.

Oh and I forgot- did you look for hints of a detached patch right off the tip of the Easter Veil, near the one you saw? Again congrats as these features are only seen in top notch images....

[jetstream]

Hint: Sh2-94

In the 10" I felt something was there and the 15" confirmed it, this is pretty hard. Susan Young is s great observer and the picture is from her report. Here is the OIII response which helps us look in the right place....

http://sandandstars.co.za/2017/07/26/cygnus-other-snr/

 

Edited August 26, 2019 by jetstream

[jetstream]

More info...

http://www.astrosurf.com/zoll/images/G65_3__5_7.html

 

Edited August 26, 2019 by jetstream

[Littleguy80]

13 hours ago, jetstream said:

Congrats Neil!

SH2-91 is not an easy target, ghostly in appearance and a worthy target for any scope. Did you see anything else in the area? there is another, tougher section that is visible

It will for sure, but...

this is not surprising actually. If your like me then after concentrating on viewing very faint nebula my galaxy abilities are lacking. I noted this over and over and now when observing galaxies they will be the primary targets for the night- at the end of a session I might sky cruise nebula though.

Stephans Quintet is easier in a 10" than SH2-91 for me- I can get 3 very faint overlapping cores with the 10" and an ortho for best views.

Oh and I forgot- did you look for hints of a detached patch right off the tip of the Easter Veil, near the one you saw? Again congrats as these features are only seen in top notch images....

Thank you, Gerry. 

haha SH2-91 seemed right on the limit but I'll give the tougher section a shot

Very interesting comments on observing galaxies after nebula. The galaxies I did observe afterwards didn't seem to resolve well. The only faint one I got was Barnard's galaxy which was more like a faint neb than a galaxy. I put it down to transparency dropping off on the night. I observed Stephan's quintet last December. The 9mm BGO picked out 3 faint cores in a triangular configuration if memory serves. 

The circled section is what I observed. Is there further nebulosity to see?

[jetstream]

51 minutes ago, Littleguy80 said:

Is there further nebulosity to see?

Keep looking......

[Froeng]

Great report Neil and a very inspiring follow-up discussion!

I am kicking myself as I have spent the whole of the bank holiday weekend shored up at home with a bad cold! I must have missed 30% of this year’s observing opportunities as it’s been brilliant weather! 

Your skies seem to be extremely dark. What bortle class is it?

CS, Frank

[Littleguy80]

1 hour ago, Froeng said:

Great report Neil and a very inspiring follow-up discussion!

I am kicking myself as I have spent the whole of the bank holiday weekend shored up at home with a bad cold! I must have missed 30% of this year’s observing opportunities as it’s been brilliant weather! 

Your skies seem to be extremely dark. What bortle class is it?

CS, Frank

Thanks Franks. Sorry to hear you’ve not been well. Hopefully you’ll get plenty of clear skies now the season is underway. I don’t have an SQM meter but I think the skies at my dark site would be between Bortle 2 and 3 depending on conditions on the night. 

[scarp15]

There are definitely aspects for other features / parts that constitute for the Cygnus Little Veil that are detectable and as Gerry has implied, the sand and stars link is a good reference. I have grasped the Little Veil in my 8" F6 dob, this though was based on becoming familiar after a succession of attempting to observe it in my 14". 

[Littleguy80]

18 minutes ago, scarp15 said:

There are definitely aspects for other features / parts that constitute for the Cygnus Little Veil that are detectable and as Gerry has implied, the sand and stars link is a good reference. I have grasped the Little Veil in my 8" F6 dob, this though was based on becoming familiar after a succession of attempting to observe it in my 14". 

I’m pleased to hear you’ve had success with your 8”, Iain. One of the Astro society members commented that he’d tried and failed to see SH2-91 in his 24”. Did put some doubt in my mind about what I’d seen. His attempt was on a different occasion to mine though. These faint targets are very dependent on excellent transparency so it doesn’t seem that odd that a 24” could fail to pick it up. I’ll definitely be revisiting and trying to see more!

[Littleguy80]

I think the one thing I’d like more than anything on a dark site session is a really experienced DSO hunter to look through the eyepiece and confirm what I’m seeing. I had that the second time I saw the Horsehead. It really helped to have confirmation plus the questions she asked   about what I was seeing through the eyepiece actually led me to see even more detail. 

Having said that, my SGL mentors have brought me so much further than I ever thought possible  

[scarp15]

Aperture on this subject is completely valid of course and yet there many more considerations, some as mentioned in your report Neil. The very first attempt I made to look for SH2-91 to be honest I was a bit clueless, research is everything. Equally exact positioning, the use of a high quality OIII filter such as Lumicon (former / traditional or recent improved version), multiple successive repeated attempts, patience, complete concentration etc. Exit pupil, eyepiece, dark adaption and following a period for observing faint / very faint nebulae - which makes your visual responses much more sensitive, averted vision. Most of all, knowing that something is there. Perhaps one error by some, is an expectation that this super nova remnant, will be just a bit fainter than the more famous one. Then of course Cygnus has to be high, transparency very good and SQM-L readings of perhaps at least 21.3 mag.

It is helpful to sometimes have someone to actually verify what you are seeing. Then however it really does commit you to concentrate and then consult with SGL friends to frame a sense of what may have been encountered. The great thing about this is that each time we go out there, we are always learning.