First Light for my OO/Helmerichs 300mm Newtonian: 15th Aug 2021

[Captain Scarlet]

Last year, during lockdown, I replaced the 12” mirror on my blue-tube SW newt with an OO mirror. The OO had a longer FL than the SW original, so I ordered a custom-specified carbon tube from Klaus Helmerichs and in the (long) meantime I drilled a new focus-hole in the blue tube as far up the tube as I could. That was fine for a while, but only used about 10 inches of the available OO aperture. With the new tube finally in my possession only recently, I finished mating the cell to and installing the focuser, finder-brackets etc a month or so ago, and since then have had two aborted attempts to get First Light for the new set-up. At the first attempt, my battery ran out of juice just as I achieved alignment on the second star. The second attempt, 3 nights ago, saw the whole tube dripping with dew-water and the primary itself completely dewed-over before I’d even begun alignment.
Finally, 2 nights ago, on 15th August, everything lined up and I had a most enjoyable session.

Chiefly thanks to SGL’s Observing Reports, I’ve been accumulating a list of targets over the last few weeks, so if you see unusual something below that you recently reported or read, it was probably partly those reports whence I stole my inspiration. (I’ve just realized, on re-reading and editing, that only one object listed below fits the “unusual or off the beaten track” category, but I put so much effort into creating the fine words in this paragraph that I’m keeping them :).

My equipment was: OO 300mm mirror in Helmerichs carbon tube with Paracorr2; AZ-EQ6 mount on Berlebach Planet tripod in Alt-Az mode; Nexus DSC control unit, directly used rather than via, say, SkySafari; Telrad and APM 8x50 finders; kitchen cloth and hairdryer for dew mitigation (both used during the night). The new tube has saved about 6kg, bringing the total OTA weight from 28kg to 22kg. It may not sound much, but it’s certainly noticeable lifting it into the rings!

 

 

Alignment - I succeeded in aligning on Polaris and Markab at the second attempt after making my usual mistake whilst selecting the second alignment star: pressing “OK” instead of “0” to select the second star before slewing to it: this effectively tells the unit “OK the second star is now centred”, while the scope is still pointing at the first, causing a fatal-error message and necessitating a complete switch-off and start again.

Alignment finished, I was ready to go. During the night I mostly used my Nagler 31 and Ethos 13, with Oiii-fitted Panoptic 24 for the Veil. Lovely and dark with the Moon fairly low, the MW was clearly on view.

Jupiter - First look was at Jupiter, still with my 18.2mm alignment eyepiece, for 100x. Judging from this view it was clear that seeing was only so-so. It stayed like this all night, for Jupiter and everything else. Better than clouds though. There was plenty of atmospheric CA, mushy wobbly edges and barely 2 equatorial bands on display. 4 Moons all there of course.

Saturn – Saturn was mush the same, though I did take time to look out for his Moons which I’ve never done before. Titan, Rhea and a background star were evident, firsts for me, and perhaps Iapetus though that was further afield and I wasn’t sure.

Barnard 142/143 “E” dark nebula – Never having heard of this but having seen images and read that it should be easily seen even through binoculars, I slewed to it, a little NW of Tarazed, still at 100x and 0.62 degrees FoV. The dark “E” is apparently about the size of the full Moon, and with only a touch more FoV than that, I couldn’t make the “E” out at all. Putting in the Nagler 31 for 59x and 1.4 degrees allowed a bit more background for comparison, but I still wasn’t convinced. Grabbing my 15x56 binoculars worked, though: it was definitely there, dark void-channels against a field of stars and diffuse background forming an upside-downish E shape.

M22 globular and M11 Wild Duck Cluster – I remember @Stu chancing across M22 with his bins a few nights ago from his new dark home so I had a quick look, but only a quick one at low mag (59x) as I was impatient to see the Veil, so I didn’t bother changing up the eyepiece. M22 nice, I’ll have to revisit it with more intent. Similarly for one of my favourite open clusters, M11, the Wild Duck Cluster, so-called because of its series of lines of stars in “V”s. Lovely and angular as ever with its single brighter star.

The Veil – I first saw the Veil around this time last year through a Heritage 130p for which I was providing temporary accommodation while its owner moved house. I saw it a little later with my SW 12” and Oiii filter and was amazed. This night, it didn’t disappoint, through the Panoptic 24 plus Oiii. I started on NGC 6992, part of the Eastern bit, without the filter, and was able to quite clearly see it without the filter. With the filter, absolutely superb! I moved across the the Western part, NGC 6960, and again it was lovely with the embedded star 52 Cygni. I followed it up and down getting a bit lost in the process so wasn’t really able to name or recognize the various smaller features. The filaments weren’t perhaps as sharply-defined as I remember from last year, I guess from the poorish seeing, but still a wonderful sight.

Pi Aquilae - Recalling @John’s mention of Pi Aquilae (very tight double) from some time ago I had a quick look for it, having put in my Ethos 13 for 141x, but there was no chance of a split, stars weren’t tight at all.

At this point I pressed a wrong button on the Nexus DSC repeatedly, thinking it was the “slew up” button, and ruined its notion of where we were, so I quickly had to re-home the mount and do another alignment. Having had quite a lot of practice, I did this quickly, and resumed my list.

M52 – a familiar sight now with all my viewing of the Nova in Cassiopeia, very nice. Like so many OCs, there is a single bright star.

M57 Ring Nebula – I hadn’t actually looked at the Ring Nebula since my very first time three years ago, my first-ever target with my then-new 12” SW newt. It made me gasp then, and it did again this time. I even said aloud “Wow”. It’s so bright, and there even seemed a bluish tinge to my eye.

M27 Dumbbell Nebula – Similarly to M57, I haven’t seen this since a first look ages ago, and I’d forgotten how BIG it is. And so bright again.

M13 Great Hercules Cluster – M13 I have returned to again and again, and have used it as a showcase object for guests, it’s usually their favourite. I generally start off by asking them “you see that smudge just there?”, and they normally can see it naked eye. I then move up to binoculars, where it’s a brighter larger smudge, and finally I amaze them with the full twelve inches’ view. The “Coronavirus in the sky” one called it this time last year. My purpose this night was to see the Propeller, which I have seen before but it’s always a bit tricky. As I readied my self to start concentrating, I looked away briefly for some reason, and when I returned my eye to the eyepiece, it had completely disappeared! I looked up: dratted clouds!! An increasingly thick patchwork was creeping across from the NW, so I gave up on M13 and decided to finish my night looking East before all was subsumed.

M31 Andromeda Galaxy – naked eye-visible, and with M110 visible in the binoculars, with the Nagler 31 installed for my widest-possible 1.4 degrees at 59x I could easily see various lanes in its structure. M32 was especially bright.

I finished off the evening with the 15x56s, taking in Kemble’s Cascade, the Coathanger (naked eye too), the (now rather dim) Nova in Cass.
Packing up from my South-facing site around the back of the house takes 25-30 minutes, mostly with up to 10 trips to and fro carrying tripod, head, OTA, weights, eyepiece case, cables, controller, etc etc. Why haven’t I just got myself a wheelbarrow to make perhaps one or two trips only? Off to the local hardware shop I think.

The Nexus DSC in “driven-mount mode” has some annoying glitches, such as only deciding to start tracking perhaps one in eight times once an object has been decided and slewed-to. You have to keep selecting the object as it drifts away by pressing OK until suddenly, randomly, it’ll start tracking. But its ability to select from any number of esoteric catalogues is extremely useful. And its “nearby stuff” feature is good too.

A satisfying night. I turned in around 3am.

Thanks for reading, Magnus

 

Edited August 18, 2021 by Captain Magenta
added pics

[John]

Excellent report Magnus - I enjoyed reading that

I can see that you are going to have lots of amazing sessions with that scope as the year progresses and the darker evenings arrive.

 

[Sunshine]

Enjoyed reading that, what a scope! I need a light bucket.

[markse68]

Your new scope looks really beautiful  Magnus and sounds like you’re going to have a lot of fun with it- really nice job you’ve done on it

Mark

[globular]

Good read Magnus. Lovely looking scope. Are you 11 feet tall? Must be something like that to reach the eyepiece?

[jetstream]

Excellent report!

Eagerly waiting for more!

[JeremyS]

That looks an amazing setup Magnus.

Any issues with the AZEQ 6 carrying the OTA (apart from finger trouble - been there 😊)? And no bumping into the tripod?
what’s the screw head on the alt locking capstan - more torque?
 

Looking forward to more reports 👍🏻

[Captain Scarlet]

8 hours ago, globular said:

Good read Magnus. Lovely looking scope. Are you 11 feet tall? Must be something like that to reach the eyepiece?

Haha I am 6’1”. It’s not too bad actually. Anything up to about 49 degrees altitude is fine. I have a small set of steps for anything higher, and never need to go beyond the first step.

[Captain Scarlet]

39 minutes ago, JeremyS said:

That looks an amazing setup Magnus.

Any issues with the AZEQ 6 carrying the OTA (apart from finger trouble - been there 😊)? And no bumping into the tripod?
what’s the screw head on the alt locking capstan - more torque?
 

Looking forward to more reports 👍🏻

Thanks Jeremy. The Mount handles the ota with ease actually, and in fact was also fine with the previous steel-tube incarnation at 6kg heavier. I’ve never had a problem.

The screwdriver head you notice is yes exactly for that purpose, it’s the handle of a Stanley Fatmax modular screwdriver to allow for extra leverage, I find the original capstan bars don’t allow enough, especially trying to undo.

[Captain Scarlet]

9 hours ago, markse68 said:

Your new scope looks really beautiful  Magnus and sounds like you’re going to have a lot of fun with it- really nice job you’ve done on it

Mark

Thanks Mark. Another thing about the new setup is the fact it’s much stiffer. The old steel tube was annoyingly flexible and if I could be bothered I had to recollimate every time I adjusted eyepiece or altitude. No such problems with this, even with the monster Nagler 31!

[JeremyS]

19 minutes ago, Captain Magenta said:

Thanks Mark. Another thing about the new setup is the fact it’s much stiffer. The old steel tube was annoyingly flexible and if I could be bothered I had to recollimate every time I adjusted eyepiece or altitude. No such problems with this, even with the monster Nagler 31!

How would you say the OO carbon fibre tubes compare to Helmerichs’s in terms of rigidity and weight, Magnus?

[Space Hopper]

Thanks for sharing, that was a good read.

I'm surprised by your quoted weight figures of 28kg then 22kg for the ota. The AZEQ6 must be about maxed out with that ?

22kg seems heavy for a 12" carbon fibre scope ?  OO's own CT12L is quoted as about 19 kg with rings and thats quite a heavy tube, and i thought

a Helmerichs tube would be quite a bit lighter than that ?

But anyway its a super looking setup you have there, and hopefully it will yield even more spectacular views in future sessions.

 

I've thought about doing something similar myself by trying a mid sized Newtonian on an alt-az mount, and

recently sourced a nice OO CT10 (short)  which weighs only 12kg.

Unfortunately its too big and unwieldy, certainly for my DM6 alt-az / Planet combo.

It would tip over if i used it in the field, and i would need a counterweight and i don'y have that option.

So i'd either have to look at a new mount option (RA AZ100 ?) or let the CT10 go and sell it on. Difficult one.....

 

[Captain Scarlet]

2 hours ago, Space Hopper said:

Thanks for sharing, that was a good read.

I'm surprised by your quoted weight figures of 28kg then 22kg for the ota. The AZEQ6 must be about maxed out with that ?

22kg seems heavy for a 12" carbon fibre scope ?  OO's own CT12L is quoted as about 19 kg with rings and thats quite a heavy tube, and i thought

a Helmerichs tube would be quite a bit lighter than that ?

But anyway its a super looking setup you have there, and hopefully it will yield even more spectacular views in future sessions.

 

I've thought about doing something similar myself by trying a mid sized Newtonian on an alt-az mount, and

recently sourced a nice OO CT10 (short)  which weighs only 12kg.

Unfortunately its too big and unwieldy, certainly for my DM6 alt-az / Planet combo.

It would tip over if i used it in the field, and i would need a counterweight and i don'y have that option.

So i'd either have to look at a new mount option (RA AZ100 ?) or let the CT10 go and sell it on. Difficult one.....

 

I've dug out my measurements and calculations. My weights quoted above are "all in", in other words including the weights of not just the tube+mirror, but tube, mirror, mirror-cell, telrad, finder, paracorr, eyepiece, rings and dovetail. Just the rings and dovetail you can see amount to 4kg. My memory did unwittingly exaggerate slightly, the before and after weights are 27kg and 22kg actually, assuming an Ethos 13 as the eyepiece. The table below shows the breakdown:

At 27kg yes I guess the AZ-EQ6 would be close to its limit. But having used it like that for 3 years, it's never given me any problems at all, even when unbalanced. Obviously at 5kg less things are better. The OO mirror is lighter than the SW one because its glass slab is actually only 300mm diameter, as opposed to the Skywatcher's 309mm (bevelled down to 305mm reflecting surface).

Edited August 18, 2021 by Captain Magenta

[Captain Scarlet]

1 hour ago, JeremyS said:

How would you say the OO carbon fibre tubes compare to Helmerichs’s in terms of rigidity and weight, Magnus?

That I couldn't say Jeremy - I've actually never seen an OO tube. I'm not too concerned about the weight: it's the stiffness I was really looking forward to. The 5kg weight saving is a bonus.

[John]

My 12 inch F/5.3 OO tube assembly weighs 17kg complete with mirrors, tube rings, finder and focuser.

 

[Space Hopper]

@Captain Magenta thanks.

That explains it : it was the original SW tube that had all the weight. 10kg for just the tube is some weight !

I've had 3 OO scopes, a 10" F4.8 and F6.3 and a 12" F4 all in steel tubes. OO tubes are very light, i bet the 12" F4 only

weighed 3 or 4kg, maybe less, but with that lightness comes some flexure. Having said that i never noticed my 12 flexing

or losing collimation that much, but maybe my 53 yr old eyes didn't notice it !!

The new 10" (purchased used) is the CT F4.8 and i'm told the carbon tube is a similar weight to a steel but obviously much stiffer.

I just need to put it to the test !!

 

[dweller25]

Fabulous setup @Captain Magenta 👍

[F15Rules]

Great report, Magnus, a lovely read.

And you've achieved a first for me..I actually found your excellent new ship's funnel, sorry, reflector, a really nice, quality looking scope!😂

Dave

[wookie1965]

Magnus that is a beautiful set up performs and looks amazing. 

Great Report some of those objects especially the clusters must have looked spectacular. 

Paul 

[Captain Scarlet]

2 hours ago, F15Rules said:

Great report, Magnus, a lovely read.

And you've achieved a first for me..I actually found your excellent new ship's funnel, sorry, reflector, a really nice, quality looking scope!😂

Dave

Thanks Dave

It really is s nice-looking object and it’s close to what I want it to end up as, both form and function. The only thing that bothers me is the mirror-cell. It’s the original SW one and it’s only just, actually maybe not quite, adequate. I’m vacillating between making my own, or splashing out on a teleskop-express custom jobby. I think I’ll probably fabricate one in due course.

M

[CraigT82]

Great report Magnus. I'm a bit disappointed to see that the thread title wasn't "First Light for Triggers Broom" but it'll do as is I suppose! 

Seriously nice looking scope. Regarding the mirror cell, I have some preliminary designs sketched up in AutoCAD if you want to take a look? My intention is to fabricate one for my SW 12" mirror which is larger as you know, but might give you some ideas. Let me know. 

Cheers 

[Stu]

16 minutes ago, CraigT82 said:

Great report Magnus. I'm a bit disappointed to see that the thread title wasn't "First Light for Triggers Broom" but it'll do as is I suppose! 

Brilliant! 🤣

[Astroscot2]

The orion CT tubes are very thin, only 2mm if I recall, I had to insert an Inner ring to strengthen the tube around the focuser and invest in longer dovetails as the scope hade so much flex, fror viewing the original tube without modification was fine.

[Captain Scarlet]

9 hours ago, CraigT82 said:

Great report Magnus. I'm a bit disappointed to see that the thread title wasn't "First Light for Triggers Broom" but it'll do as is I suppose! 

Seriously nice looking scope. Regarding the mirror cell, I have some preliminary designs sketched up in AutoCAD if you want to take a look? My intention is to fabricate one for my SW 12" mirror which is larger as you know, but might give you some ideas. Let me know. 

Cheers 

Funnily enough that name did occur to me. It would be too confusing though as I already have a bike with that name 😁. It’s done 43,000 miles and the only parts remaining of  the bike I originally built are the saddle and the right brake lever. Everything else including the frame has been replaced at some point, but it’s always been the same bike to me!

If I called this scope by the same name, imagine my confusion when I try to set up the bike on my AZ-EQ6 and look through it! 🤣

[Captain Scarlet]

3 hours ago, Astroscot2 said:

The orion CT tubes are very thin, only 2mm if I recall, I had to insert an Inner ring to strengthen the tube around the focuser and invest in longer dovetails as the scope hade so much flex, fror viewing the original tube without modification was fine.

Ah yes I can see what OO do to get their tubes so light, they just use the CF shell. The CF shell on my Helmerichs tube is indeed only around 2mm thick, but he’s lined it with an extra 4-5mm of hard foam to lend extra stiffness and provide a base in which to drill and mount extra things. Obviously that adds some weight.

Magnus