18Nov Another evening with a big Dob…

[alanjgreen]

Date: Sat 18 November 2115 - 0300am              Scope: 20” f3.6 Dob with paracorr2

I had been watching the weather forecast for the previous couple of days, could it be true that we were to receive a completely clear night coinciding with New Moon? (Surely not!)

“READY FOR ACTION”

I had some issues to iron out with my heating provisions on the big dob after my last couple of outings had proved a couple of things

-              Secondary mirror heater needs to be at no more than 20% (or view is impacted)

-              Eyepiece heating tape needs running on high/full power (or it is ineffective)

To rectify this I decided to convert an old straight through cigarette heater cable (from my CPC days) to fit onto the astrosystems power system of my dob. I (1) swapped the cigarette socket for an RCA plug (my rocker box has plenty of empty powered RCA sockets), (2) added an inline 3A fuse to the red wire using a “Splashproof Standard Blade Fuse Holder” that I found on 12voltplanet website (it takes those automotive blade fuses). https://www.12voltplanet.co.uk/splashproof-standard-blade-fuse-holder.html

Then I changed the wiring around on the dob so that I could pass this new cable up and over the red dot finder allowing the eyepiece heater tape to just hang there! (I found another advantage of this while in use that I can hold the tape to warm my fingers when it is not warming an eyepiece!) and tested everything was ok. I moved the dob to a new position in the shed so I would be able to get down to the horsehead as that was on my target list.

I managed to get a nap between 1600-1800 to top up my batteries!

Knowing that the Horsey would not be in position until 1 or 2 am, I decided to not start too early but by 2100 I was ready for action…

Having setup & aligned the scope using two bright stars for Nexus (using Ethos10 x200), I headed for M33. Defocusing a star showed that I had tube currents but the fan was on…

“SESSION HIGHLIGHTS”

M33 – To my surprise x200 was not too much for the conditions and M33 proved to be a “giving” target at this magnification. I could see a lovely racking “S” shape coming from the main two arms. Beyond that I could see several hinted propeller arms that make the “Pinwheel” shape. I picked up three NGCs in a triangle shape above the galaxy core. I could see two more NGCs to the top right of the core and a further two NGC to the lower left of the core, one of these was in the arm that’s spreads out to finish at another NGC out near the bright field star. I make that eight NGCs in all.

I dropped in the 8mm x250 but found this too much for my scope (at this early stage) so dropped in the 13mm (x150) which provided a better framed view. The sweeping "S" was still there but I felt the view not as good as the x200. But it was easier to handle with the reduced nudging needed.

I did try out the 21mm x100 view but this was not as good as either x150 or x200 above.

I would say that this was easily my BEST view of M33 and the scope was hot out of the box! (not at its best). I determined to come back later when the scope was cooled to the conditions. When I did return later the conditions must have deteriorated as the galaxy was not as giving as it had been in this first visit.

M31 – Next up was M31 (using the E13 x150) which I found to be giving its “usual” level of detail and no more. I could see the 2 black lanes sweeping alongside the core and was able to trace each of their paths across the galaxy as they cut to the other side. I picked up the brighter sections to the top of the galaxy that I had seen before but there was not much on offer under the galaxy. M110 had a brighter core than on Tuesday night but not as bright as the session before that when it really stood out.

NGC891 glx – This target is now on my must-see list so I popped by to take a look (especially as I was able to use multiple magnifications). I started at x150 and saw a long cigar shape fill the eyepiece, there were faint hints of the central dark lane). I moved to x200 and the dark lane became easier to see. [ I also noticed that if I positioned the galaxy in the lower section of the Ethos FOV that the central lane seemed to pop-out more easily, as the galaxy drifted up to the centre and above centre then the centre lane became harder to tease out ]. I dropped in the 8mm x250 and there was the centre lane! Again, it was “there” when the galaxy was low in the eyepiece FOV and more difficult as the galaxy was central/higher?? In conclusion, the best view of the central dark lane was with the E8mm.

NGC1023 glx – In the 10mm x200 it showed a very bright core with a nice surrounding disk. I could not pick out any detail in the disk.

NGC185 glx – At x200, this is a big galaxy. The core was bright and the disk large and faintish.

NGC147 glx – At x200, it was a challenge to find this galaxy. Got it eventually, its pretty large and very faint. I dropped to x150 and it was easier to pick out but still not easy. Compared to NGC185, this is a difficult target!

Double cluster – I have not visited this target in a few weeks and thought I better drop in before it moves out of my range for another year. This time I had the E13 x150 loaded and the view and colours were superb. I love this target and spent some time nudging around the whole area.

Pacman – I started unfiltered and while the nebulosity was visible, it was not bright enough for me so I added the UHC to the paracorr to enhance the view (which it did). Now there was plenty of lush nebula surrounding the central stars. [ I was now sticking with the E13 as the cold was setting in and eyepieces were misting up ]. I think I preferred previous views from the E21 as this time it was not quiet hitting its best!

[ I could also notice some reflections building in the lower regions of the sky as if maybe water or similar was beginning to reflect light back down to earth, conditions did not seem as good as when I started ]

Heart & Soul – I had the 13mm x150 and the UHC still in the scope, both the Heart and Soul were easily seen and showing good detail, I was able to pick out brighter clumps within the nebulas. I threw in the O3 but surprisingly this proved to be a backward step and it was harder to see them so I went back to the UHC. [Normally, I find the O3 best on this target, but the extra darkness of the O3 was its downfall last night, the conditions needed the more forgiving UHC ]

[ By now it was 0030 and my toes were cold so I closed the shed roof and went inside for a warm. I wrapped my socked feet alternately in a hot water bottle and had a quick drink of hot water – 20 minutes past and I was ready for part 2… ]

California neb – [The downside of a “pop inside” is that dark adaption is lost so this target took a bit of time to “get into”]. I started with the 13mm & UHC and found the nebula to be very clear. As I traced around its large area I could see brighter areas and what seemed like long strands running inside it. I swapped to the Hb filter as this is a target where it can help. I found the nebula redder and harder to see but there did seem to be more detail and patterns within it with the Hb.

[I tried a couple of other nebula targets showing in sky safari with underwhelming results. I managed to miss my chance to look at the Pleiades on the way past so I must try harder next time I am in this area. ]

Crab M1 – This was my first time with x150 on the crab nebula. I found the nebula to be big and hazy. It seemed to have varying tones of darkness running through it and I should have put more magnification but my eyepieces were cold by this point. From memory, I think that the nebula is easier to see in the E21 x100, but that x150 brings out these varying shades that cannot be seen at lower magnification. Once it gets better placed for an earlier session, I look forward to getting the 8 and 10 mm on this target.

Flame neb – Right, now getting to the business end of the evening. I am in better shape than the previous session as I have a nice warm E13 in the focuser and that means Alnitak can be moved out of the FOV and give me a better chance to see the objects on offer nearby. Starting with the Flame, I have E13 and Hb filter loaded. As soon as I arrive at Alnitak, the flame is clearly seen sitting to the side Its BIG. [this I need to ponder as I did see the flame in the CPC1100 at x100 but the view in the big dob seems on another scale!]. I nudge Alnitak out of view and the Flame nebula really is large and can be seen in direct vision. I did pop back later with the UHC loaded and found the flame easy to pick out once again.

Horsehead – Onto the horsey. I used Nexus to position me in the right place and quickly located the field star pattern. [ For anyone who read my earlier session reports, I WAS IN THE RIGHT PLACE the first time I came here and managed to convince myself that I had made a mistake with my well-rehearsed star hops from Alnitak – too tired on that occasion].

Over the next hour or so, I tried 8mm x250, 10mm x200 & 13mm x150 (each fresh eyepiece swap resulted in a wet eyepiece that the heater took a few minutes to burn off) . I found a dark patch in the right place with the 10 & 13mm eyepieces but it was only with averted or sometimes with scope movement. I tried both Hb and UHC filters and found both revealing this dark patch, the Hb seemed to show the nebula lane better and that should mean the dark area is easier to see. I ended up feeling disappointed on this occasion! The nightmare of wet eyepieces after midnight doesn’t help you get relaxed at the eyepiece so it feels that I will have to wait until I can get to view this position before midnight in a month or two to get my best chance to “see” it in direct vision. Until then I think I will take it off the menu and add some other more achievable targets as I do feel that I missed out on some great targets last night to wind up for this last chance horsey play. The chances we get are few and far between that I don’t like putting all my eggs in a one basket like this. 

M42 Orion neb – Onto the Orion neb for the crescendo of the evening... If the horsey left me feeling down then I knew M42 would be a good way to get that final lift that warms the heart before you pack up for the night. I had the E13 x150 and UHC filter in the scope. The E13 had warmed up so mist would not be an issue. This is my first time on M42 with the big dob. WOW, I was not disappointed. The nebula filled the eyepiece with the central region almost white (it was so bright), falling away to the sides there were many shades of grey. A dark black lane pierced into the nebula from the M43 area and stood out really well against the white central area of M42. I nudged around and took in the view. I did not see any green colour as some people report but then their eyes may be younger/better than mine (who knows) but the shading of the various greys and the white/black junction were astounding clear. I decided to wait for another night to throw in the 8 and 10mm to really get into the  textured cloud that surely waits in that bright central region. By now I was cold, tired and running low on brain charge so decided to call it a night.

"EPILOGUE"

The roof closed to the sound of crushing ice as it moved along its tracks. The UTA & upper parts of the shroud were covered in ice. My desk in the shed was covered in a layer of ice as was my eyepiece “really useful” box. I fetched a towel to wipe the scope down.

Checking the secondary view through the focuser it was clear, no ice. I left the scope uncovered and set the dehumidifier running on its timer and went to bed (with my hot water bottle refilled). I am finally happy with my heating arrangements for the winter.

Sorry it’s a long report but something may be useful,

Alan

[Victor Boesen]

What an amazing report! Nicely written and the observations were well described.

[John]

Great report Alan - I really enjoyed reading it

 

[alan potts]

Yep, great minds think alike, Great report as John has said. Like you I was disappointed in the HH and for sure will not waste the amount of time  hunting it again, a quick look yes but not a hunt.

Alan

[Paz]

Great report, I would be interested to know  roughly what naked eye limiting magnitude was for this session?

[alanjgreen]

50 minutes ago, Paz said:

Great report, I would be interested to know  roughly what naked eye limiting magnitude was for this session?

At. 0100 I could see m33 naked eye. I could see the usual m31 and double cluster at 2115 straight after I got outside but not m33 at that time.

[alan potts]

Sounds to me Alan as if your sky was on a par with me here on best nights, I can often see M33 but it is a fair bit higher in the sky for me which will help, as indeed it would have done for the HH.

Alan

[Paz]

20 minutes ago, alanjgreen said:

At. 0100 I could see m33 naked eye. I could see the usual m31 and double cluster at 2115 straight after I got outside but not m33 at that time.

Thanks, that's a lot better than I've got, I'm going to have to travel more!

[Littleguy80]

Fantastic report, Alan. I see you also fell victim to cold toes! I don’t mind a target or two that I couldn’t find or get the views I wanted. It immediately gets me thinking about the next session and how I might change my approach. I know we’re going have another cracking report with a successful viewing of the HH from you soon  

[niallk]

Great report / write up 

[FenlandPaul]

Lovely report of an enviable night, Alan. It kept me company during a solo dinner on a business trip!!

Paul

[bish]

Wow, great report. Looking out at my cloudy and light polluted sky, I read a report like this and it reminds me how good astronomy can be!