25Nov Big Dob exposes the delights of Orion

[alanjgreen]

Date: Sat 25 November 2245 – 0230am              Scope: 20” f3.6 Dob with paracorr2

Introduction

This is a continuation session to my November posts “An evening with a big dob” & “Another evening with a big dob”. In them I have visited the same targets and tried to pick out details un-noticed or not visible in the previous visits. Astronomy is a waiting game and good things come to those prepared to wait…

The session was unplanned, I finished a movie at 2230 & happened to look outside to clear skies. Having been on a “no star diet” all week, I decided that I was “going for it”…

The scope was “ready” in the shed and I just needed to collimate (a breeze thanks to Howie!) and shove the roof open.

It was cold (but not that cold) and I was running the secondary heater on 20% and had my eyepiece heater on full (see previous posts for the heater settings learning curve).

 

A night of Wows

M33 glx - Once Nexus was aligned, I swung the scope around to M33, I had the Ethos10 (x200) in the eyepiece and instantly saw that the conditions were good. With my semi-open pupils I could see a lovely thick “S” shape coming from the main arms. The 100 degree field was not enough, M33 was bulging out of my view on three sides and I had to manoeuvre around the galaxy looking for my “recognition points” to orientate myself and to tick off the things I have seen before.

I dropped down to the Ethos13 (x150) as this gave me more time “to see” the galaxy. There were so many NGCs on offer that I had to do a sketch (a rarity for me). I picked out eleven NGCs within M33 (beating my previous 8) and marked them with ticks on my sketch. I drew four partial arms on the sketch to help map the ticks to an image in the morning.

I did try the Ethos21 but it did not bring out the same detail that I could pick up in both the E10 & E13.

NGC 891 glx – Onto the cigar shaped NGC891, with the E13 the galaxy filled 75% of the view and the dark central lane was clear in the centre and could be teased out further to the sides by positioning the galaxy low in the eyepiece and ”looking down on it”. I still think that I have seen the galaxy clearer (as a darker grey) on a previous occasion but the central lane was much easier tonight. I tried the E10 and although magnified the view was no better.

Double cluster – As I was nearby and I had the E10 loaded, I though “why not” lets see the double cluster at x200… What I discovered was a really enjoyable view, clearly the two clusters are huge at this magnification but the background is so black that the stars really call out to you! The central areas revealed a few new smaller stars on top of the “usual patterns”. I noted two lovely bright red stars in NGC884 that really stood out as a nudged by.

M76 neb – Onto the little dumbbell that was bright and easy to find but it was an underwhelming target and I quickly moved on…

Pleiades – After all the messing with the horsehead on my previous night out, I determined to bag some old favourites that I missed out on last time. The Pleiades is a joy in any scope and tonight was no exception. The stars were so bright against the dark background provided by the E13, lots of nudging needed to get around this nearby group of stars but it was enjoyable. The nebulosity on offer was less than I have seen in the past with this Dob but it was visible in small quantities around the brightest stars. I will be happy to come back again for another look!

California neb – After @scarp15 post “Variations on the California”, I could not miss it out on my way across to Orion. I had the E13 loaded (x150) with Astronomik Hb and spent a good twenty minutes moving up and down the nebula, tracing the visible lanes that run within it. The ends are clearly distinct and curvy and you come across the occasional bright patch or lane every now and then. Its hard to describe as what you see is not really any definable shape or object? Comparing these bright patches to my location in Sky Safari5 showed them to match to brighter areas within the nebula image. [ It really is great to look down on the tablet and see where the dob is pointing, it adds weight to what you are seeing at the eyepiece for sure]

Some cloud was coming over so I bagged a few open clusters whilst hoping that it would “go away”, M38, NGC1907 & M36.

M1 crab – with the cloud gone I moved onto the crab. I tried E13 & E10, unfiltered and Astronomik UHC concluding that the E10 unfiltered gave the best view (x200). At x150 there was a large grey patch with no distinct edges but at x200 I could sense dark shapes cutting into the grey patch and perhaps some outline was trying to come through. It didn’t of course but I was on the edge of maybe seeing some shape. I’ll come back and try the Ethos8 on it later in the season, it may get a bit more on the right night.

NGC2024 Flame neb – I had determined to spend more time on the Flame tonight after the faff of the horsehead on the previous two nights and I was not disappointed . I swung the scope over and even with no filter in the paracorr, the flame was dark and clear to see! I threw in the Hb and with the E10 (x200) loaded it was so much easier to have Alnitak out on the edge of the view. What can I say, the flame is so BIG and looks like an “upside down tree”. The tree trunk was wide and black standing out against the nebulosity clearly. The branches of the tree were not as clear but the overall tree shape was lovely. I came back after the horsey and tried with the UHC for comparison. The UHC view was on a par with the Hb from memory, I did not note anything extra from either filter. Both filters did improve the unfiltered view but I am still astounded that I saw it with no filter at all. In conclusion this target is so much better than the horsey and will be re-visited in future to see if I can tease more of it out. Its such a shame that Alnitak is so close, it really makes this a tricky target. There is no comparison in the results achieved with this 20” compared to my old 11” on this target!

Horsehead – (unfiltered E10) I had to try the horsey when I was just a few nudges away at the Flame.

 (1)   E10 and no filter - I tracked over to IC434. There was not a lot to see, maybe some hints of the nebulosity but no horsey.

-           (2)     E10 & Hb – Horsey seen as a large dark black shape within a bright lane of nebulosity. As I moved to the horseys location, I could see the dark shape coming and going straight away The edges of the shape were not well defined so I played around with how best to see it. The most successful approach for me, was to come up from Alnitak following the gas lane and go past the horsey to the next bright star. Now reverse and move slowly back along the lane until a black shadow enters the bottom of the eyepiece. In this low eyepiece position was the best view of the “shape” as it came higher up the eyepiece the dark patch was there but moved more to averted vision and higher in the eyepiece it was gone.

-           (3)    E13 & Hb – yes, the horsey was seen (steps as above)

-           (4)    E10 & UHC – yes the horsey was seen (steps as above), view more difficult than with Hb.

M42 Orion neb – After spending/wasting less time than previously on the horsey, I was moving onto M42 with great expectation after my initial viewing with the big dob last week. I had the E10 (x200) and UHC loaded. Its hard to describe in words what I saw as it is so much different to what you get in 11” but you know that I am going to try…

Well, lets start by going back to what I saw last time out with the E13 (x150) and no filter…

“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. The shading of the various greys and the white/black junction were astounding clear.”

And now, M42 with an E10 (x200) with Astronomik UHC filter

“The central area looks like a baby bird with its mouth open waiting for a worm from its mother, its incredible. The bright white is now a bright grey colour but there is more texture, so many twists and turns within this nebulosity, but you just keep seeing the baby birds head shape – its mesmerizing. Moving away from this central area are the usual two wings and at this magnification you have to trace them away to the ends. But now there is this third lane moving away at 90degrees from the wings, it ends in a dark black blob of hydrogen (never seen this before) then there is a out-swinging lane that moves around the back almost joining the outstretched wings. There are so many different shades of grey, each revealing a new pattern within the nebula. “

M43 – it just can’t compete with M42 so its just “missed” as you cannot take your eyes away from M42. Once you focus on this region then you are drawn to the blackness of the jet black hydrogen coming down and piercing into the nebula to create the baby birds beak shape.

I removed the filter and had a crack at the trapezium. Five stars were easily seen but the sixth was not there. I was fighting a bit of passing cloud by now and then all the stars were gone…

Elated

I could have hung around for a while to see if it cleared, but I was feeling elated after M42 and thought “you won’t beat that!” so closed the roof and packed away.

The UTA was slightly damp, the surface of my desk was damp to the touch so there was dew but it was not as bad as on the previous “evenings out with a big dob”. This probably contributed to the better results achieved tonight.

Time to boil the kettle and get that hot water bottle ready for bed…

Hope you find this useful,

Alan

[scarp15]

Brilliant report Alan and one aspect that is clear based on some of the influx of reports, is to the extent of clarity there has been when observing M1, testimony to the great transparency conditions. I think I had observed M1 with my 21 and 13E, no filter, would have been interesting to have engaged a little more time and at higher power. The Orion nebula to, Neil in his recent report reminded me that I had seen a hint of green within the nebulosity. Your eyepieces were clearly performing without issue last night. The Flame nebula was amazing, it seemed to work better for myself without a filter and even with Alnitak on the edge of the field of view, nebulosity was apparent. Cruising along the California I could actually relate to aspects of some of the recent monotone images, that equally make for a superb reference, as posted in the imagers section.  You must live within a superb rural location Alan, my parents use to live in the Eden valley, north of Penrith. 

[Hayduke27]

I absolutely love M42, and the observing night is rare that I don't take a look at it.  I really like your description of the "baby bird" pattern, I am going to look for that on my next go.  You describe a "dark black blob of hydrogen".  I have had a lot of observing in the past where I swore I could see swaths of total blackness covering up everything behind them, but wasn't sure if that is what I was actually seeing or if it was a product of my imagination.  I think I am going to have to start paying closer attention to these dark spots, it seems I may be overlooking nebulosity!  Great report!

[estwing]

They will be calling it golden weekend after all these stunning reports....big glass gets big memories! Superb! More,more,more!!!

[John]

Great report Alan

I like the "baby bird" description of that dark inlet into the heart of the Orion Nebula

Many years ago I read that the above area of the nebula is known as the "Fishes Mouth" so thats what I've tended to think of it as but a hungry baby bird is just as good !

There is all sorts of detail in there if the night is good and dark and the aperture sufficient:

 

[alanjgreen]

11 minutes ago, John said:

There is all sorts of detail in there if the night is good and dark and the aperture sufficient:

 

Thanks for this John. I will try to look/note some of these (less obvious ones) next time out and report back...

[David Levi]

Fantastic report again Alan.

6 hours ago, alanjgreen said:

Hope you find this useful

I dream of a big dob so maybe in a few years time.

 

[mapstar]

Nice report Alan 

That large piece of glass is certainly delivering some great results.

M33 has so much in it and worth spending some time. I must try a sketch or two sometime I just hope the clouds  are kinder over the next new moon.

Thanks for posting such a good read 

[Stu]

Cracking yarn Alan, enjoyed that. You are clearly getting the best out of your big dob, and isn't it nice to have some good transparent skies for once? Fab to be reading all these observing reports rather than complaining about cloud!  

[Highburymark]

A great report of an amazing night. Can only imagine what the views you describe are like to experience Alan.

[Littleguy80]

Awesome report, Alan. I find Orion stunning in my 130mm scope. I can only imagine how good it must look with your big dob!