4 August - Big Dob uses Night Vision to seek out Nebula missing from Sky Safari !!

[alanjgreen]

Date: Saturday 4^th August 2230-0010

Scope: 20” f3.6 Lukehurst Dob with Paracorr (fl = 2089mm & f4.1).

Eyepieces: 55mm (f2 x38). Night Vision: PVS-14 with Photonis 4g INTENS.

Filters: Astronomik 6nm Ha CCD.

Moon: 0%

 

Make a decision and have a Plan

With a clear night forecast, I had spent the afternoon deciding between (a) Borg89 and planets, Sagittarius or (b) Big Dob and Cygnus? I even thought about doing both!

Anyway, I decided on Big Dob and taking on more nebula in and around Cygnus.

My plan was to use “The Astrophotography Sky Atlas” (by Bracken) and try to find nebula that are missing from Sky Safari (which seems to be quite a few!). I marked the pages of interest with yellow post-it notes so I could find them quick with my torch later.

 

Alignment Woes

Last time out I was not quite happy with the collimation, so I spent an extra iteration with my Howie Glatter laser & TuBlug to get everything spot on. Note that I always collimate with the Paracorr2 in the scope as it does move the laser pointer when added to the light path.

Once happy with the collimation, I pushed back the shed roof and was greeted with thin wispy clouds passing over . Finding two nicely spaced alignment stars for my Nexus push-to was not going to be easy. Luckily after a couple of minutes Alderamin appeared and I quickly aligned to it as the first star, I then get Albireo as the second star and was good to go. I confirmed my alignment with a quick look at M56 with the Ethos10.

 

Straight into Gamma Cygni

I swapped the ethos for the 55mm Plossl and attached the PVS-14 NVD to the eyepiece. I attached the Astronomik 6nm Ha CCD filter to the Paracorr2 and pushed the scope onto Gamma Cygni. To my surprise the nebula was sharp and clear, so I nudged around to get my eye in playing with the “gain” (on the NVD) to get the most contrastiest view possible. As the gain is lowered, then the Signal to Noise Ratio is increased so more of the target becomes visible. You still need averted vision to tease out those finer details though…

Gamma Cygni gave out some great textured views and I lingered on the areas where the lush texture of the nebula was interspersed with thick black hydrogen lanes. These are the areas that catch my eye every time .

 

Heading West

It was time for my first referral to the Sky Atlas (p15) and I decided upon the Crescent and Tulip nebulas as my next targets.

Crescent – The crescent filled the 40 degree FOV of the Plossl and showed lovely bright structure within which I could see black shapes and cut-outs that revealed its finer features. With some averted vision I could begin to make out the circular upper structure and it began to appear as a “backwards number 9” shape. The detail kept revealing itself the longer I stayed at the eyepiece.

Tulip (sh2-101) – Onto the Tulip (which I have observed before but at that time I did not know it was called the Tulip just sh2-101). The view was of a “backwards C” shape filled with nebulosity. With averted vision I could see what looked like a “grasping hand” darker shape within the overall structure.

 

Back to the East

Back to the Atlas, and selecting sh2-104 & sh2-106 as I close to the shed wall and needed to go back the other way.

Sh2-104 – It appeared as a quite small brightish blob. There was some undefined shape and varying brightness within. With the sky still showing wispy cloud I did not want to waste any time changing eyepieces so pushed on to the next target.

Sh2-106 – This is a target missing from Sky Safari so I had to nudge around and hunt for it. Eventually I found a small bright patch. The patch was made of three sections. A brighter middle section and then two outer sections (one either side) of a dimmer nature. [ To make it easier for next time, I picked a star in Sky Safari that was in the centre of the circle showing my FOV and added that star to my observing list! ]

Checking images on the internet this morning, there is no doubt that I saw sh2-106 so I am happy about that.

Vdb-133 – next came an unsuccessful search for vdb-133 which is next to sh2-106. I hunted around but could not locate it.

Sh2-107 – then another unsuccessful search for sh2-107. It is in Sky Safari but when I centred the scope on the target there was nothing there to be seen. I nudged around a while but nothing. [ Looking on Wikipedia this morning it seems much fainter than sh2-106 so I need to try again under pristine dark skies… ]

 

Nudge down to the Veil

I did wonder whether to skip the Veil as I have seen it many time before BUT it’s just one of those objects you HAVE TO SAVOR!

(image oriented to match my view at the eyepiece)

Western Veil

As soon as I put my eye to the eyepiece I knew I was in for a treat! The upper section of NGC6960 was showing the split into three parts (I only saw a split into two on my last visit). I journeyed down the bright lane of nebula past the star to the tip, then across to Pickering’s Triangle.

Pickering’s Triangle was stunning. The wispy lanes and finer details within the triangle were just brilliant. I could see the small “E” curve to the left and the long bendy NGC 6979 to the right very clearly. Below NGC6979 were a further two small patches (one labelled “F”, the other below that).

Moving up I could see both “G” and the wispy lane to the left of “G” too. But the most memorable piece for the night was “The Thin Thread”. On my last visit I could just make it out and follow it up but tonight it was clear as day and also showed multiple threads! [ We have had a lot of rain over the past week so maybe the sky is extra clear for once? ].

Continuing up the thread it split into two forks at the top and I was able to see “D”, “C”, “B” and “A” over the top. [ I missed out looking for these last time so made extra effort tonight. I also bagged “H” as I header right to the Eastern Veil.

 

Eastern Veil

As I dropped down onto the IC1340 & NGC6995, it looked like the roof of a VW Beetle! Two parallel curvy lanes with some cross pieces and a couple of brighter blob sections (IC1340 was one of them). It was so bright, there was a lush patch of nebula bottom right just before the long bright NGC6992 came into view. This section was very bright and detailed but I kept returning to Pickerings and the Thin Thread. NGC6979 really did show its shape very well last night.

 

Propeller Nebula (DWB111)

Right, after that excitement and a check of the Atlas, I decided to seek out the Propeller nebula. This is another object missing from Sky Safari. I had had a go at finding it last month with no luck but tonight is another night!

With the aid of NGC6866, I nudged down SW and my luck was in, I found it . It was big and very bright, an unmistakable “S” to the eye. I nudged around and discovered that this area of sky is rich with long lanes of nebulosity which are mostly quite bright and traceable. Back to the propeller and with time at the eyepiece the initial “S” started to take on the look of a “double S”. I spent some time observing the Propeller and once again picked a central star from the FOV shown in Sky Safari and added it to my observing list (to make finding it easier next time). I will be back as this area was so full of nebula but the wispy clouds were returning so I pushed onto the next target…

Sh2-112 – I recognized it immediately from my previous visit. I was greeted with the “letter C shape on top of a long stick” that I had seen before but it didn’t last long. After a few seconds it faded into haze. I looked up and the clouds were thickening.

North American & Pelican – Onto something brighter. The North American is probably too big for the big dob. But I managed to nudge around and see the brighter sections before the clouds took over and my view progressively diminished more and more…

 

Thoughts of the observer.

So much for the forecast clear night! It was a pretty short session of around 90 minutes. I felt disappointed as I closed the shed roof as I was “on a roll” and had been successful finding some new (to me) targets.

The views of the Veil had been my best ever so I took heart from that and I had managed to find the Propeller which was definitely worth the effort. The area around the propeller was full of nebulosity so I will be sure to return. 

I was glad that I had added some star markers into my observing list to make my chances of revisits that much higher. It is nice to find objects but I really want to spend as much time as possible observing them.

The sky did seem a little darker last night so I think the worst of the bright summer nights may finally be behind us!

 

Clear Skies,

Alan

[emadmoussa]

Great report! 

[MarsG76]

Cool report of a short but eventful night.... those night vision units seem to get more and more popular..

 

[PeterW]

The gamma Cygni area always causes problems. I usually run at 12x or so, so the propettlor is likely on the small side for a positive ID. Good too see the bid dob is earning its keep.

 

Peter

[Littleguy80]

 Very enjoyable report, Alan. I had whiz around Cygnus last night, taking the Crsescent, Veil, NAN and Pelican. I was using traditional eyepieces and an OIII. Lots of fun though!