Captain Scarlet

I seem to be in the minority that uses a newt on an alt-az mount. And at the big end of things too: a 12” on an AZ-EQ6. Although I now have reduced the weight of the OTA with a carbon tube, it used to be a full-blown SW 300p with steel tube, coming in at over 27kg including eyepieces finder etc. I was and am able to attach it to the mount without risk on my own: I attach the rings first, then with clutches locked and OTA horizontal held with one hand at each end, I “walk” the tube into the open rings, close the rings whilst gently holding the tube in place with my body and I’m done.

A 10” being so much more wieldy should be even simpler should you go down that route.

Cheers, Magnus

After a total fog white-out this morning, the evening turned into a night of beautiful transparency. And the forecast seems to suggest the same for 3-4 nights! So this night I quickly set up my nearly grab-n-go set-up: LZOS 105 on AYO2 mount, with Nagler 31 and Ethos 13, giving me 21x and 50x. definitely a wide-field session! I also had a pair of 10x50 binoculars.

The 21x allowed me to take in the whole of Kemble's Cascade, though I couldn't get any colours (the stars are supposed to be a mixture of colours). Kemble's Cascade "ends" in NGC 1502, a rather lovely small open cluster which at 50x was very nice indeed. It contains a "ladder" of several pairs of stars that I couldn't tear my eyes away from. I spent most of my time looking at NGC 1502. Also M52 funnily enough was more visible in the 10x50s and at 50x than at 21x. Odd. A quick tour also of M13, M92, M27, M57, M44, M103, Double Cluster (mesmerising at 21x and 50x), Algieba and Castor, both last just about split at 50x. Bright stripe of MW too across the East. And nice to see little Delphinus rising in the South, along with Altair in Aquila: Summer is coming!

Looking forward to getting the 12" out over the next couple of nights.

Magnus

18 minutes ago, Olli said:

Hi stu, 

the exact dates are the 9th of September to the 19th. After doing a bit more research I think it maybe best to see if I can change the dates. When is usually the best time for the moon cycle?

Actually starting off at Full Moon is not at all bad. Full Moon means it's diametrically opposite the Sun. Which means at Full Moon, the Moon rises when the Sun sets. Which further means that from that point, the Moon rises about an hour later each night thereafter. Just 2-3 nights after Full Moon, you'll get 2-3 hours of pre Moonrise darkness, and each day gives you an extra hour. In my book, Full Moon means dark nights start really soon.

I've appended a chart of key times based on Tenerife location and those dates...

Cheers, Magnus

Superb, well done!

41 minutes ago, ScouseSpaceCadet said:

Lovely. You will only get five clear nights a year, however they will be magnificent! 😆

Enjoy. 👍

Two of those will be moonlit of course 🙂

The chart showing the data I posted a bit earlier in the thread shows “darkest nights” regularly a little bit darker than that suggested by the Atlas 2015 layer on lightpollutionmap.info . The Sunbury-on-Thames data show best values of around 19.15 whereas the website suggests 19.05. And my dark location is a suggested 21.80 and only a few weeks ago I recorded 21.97 .

So two locations at opposite ends of the scale agree reasonably well with that website (which incidentally is where Clear Outside gets its data too I think.

Magnus

32 minutes ago, PeterW said:

Are those streetlights in the background of your picture… i thought you lived in a very dark area?!

Peter

Yes they are streetlights, but about 6km away as the crow flies. They’re quite useful actually as the rightmost one is precisely due North from the house. There are streetlights in nearby Baltimore too, about 2km away, but I still get 22.0 sqm values at zenith around Easter. The odd lights here and there seem to make little difference, it’s whole city-fulls that seem to do the damage

On 15/05/2022 at 17:38, Mircea said:

 

 

 

 

Friday May 13: the evening sky was hazy, the moonlight was intense, thin clouds.

Only the main stars of the Big Dipper, those of the Leo were well visible from my yard.

And the Moon at four degrees above (blue) Spica.

Reminding the color of Spica triggered the rest of the observation session.

I took a chair, my 8x30mm binoculars and turning toward North-East I started looking for star colors.

There are many colorful stars in the Spring sky.

From the straw yellow Arcturus, to deep yellow Izar, golden yellow Algieba and Alpha UMa. 

Next was what we may  call ''The Gang of the Spring Oranges'':  Eltanin/ Gamma Dra - Kochab/ Beta UMi- Rasalgheti/ Alpha Her, gang led by Delta Lyrae.

(The blue hue of Spica was washed by the strong moonlight but in a moonless night one can admire the blue cast of this star against the pasteled white of Vega , with Regulus somewhere between them.)

 

At this point I observed with the 8x30mm binocular Delta Lyr, Epsilon 1-2 Lyr, Alcor- Mizar, Nu Dra, 16-17 Dra  as double stars and counted 18 stars in Mel 111.

I did not met yet an instrument not capable of resolving Nu Dra. I had a 2.5x Galilean spyglass, even that resolved it.

 

Next I took my three inch ''Optus'' Newtonian and observed some double stars :

-Algieba - OMG how beautiful golden yellow Airy disks and bright, perfect difraction rings.

-Alcor-Mizar , an image worth to be put in a photo album. 

-Alula Australis/ Xi UMa, resolved-split at 117x.

-This time I gazed to only Nu Dra+ Arrakis/ Mu Dra+16-17 Dra. Of course, Nu Dra was already resolved by the 6x30mm finder but also the other two stars were split at 117x with 16-17 Dra seen as a beautiful triple star.

I said ''only'' because if we look at the head of the Dragon we will notice these stars make a ''necklace'' with 39 Dra and Omicron Dra.

I use to call these chain of double stars, made up by (16-17 Dra + Mu Dra+ Nu Dra+ 39 Dra+ Omicron Dra) as ''Sigil Smaug'' or ''The Necklace of Smaug'' to honor the writings of JRR Tolkien that I like so much.

(I must admit, beside my strange night habits (noticed by some of my neighbours), I'm also a LOTR fan, I have all his books which were translated in my mother tongue.)

-Psi Dra and Zeta Lyr , Rasalgheti, Albireo, Epsilon 1-2 Lyr resolved at 70x and split at 117x

-M13, M92, Steph 1 as a cluster of eight stars 

At the end I searched the double star 16 Cyg , more because is a beacon to planetary nebula NGC 6826.

At 70x, the planetary nebula was more a hazy star. At 117x, a small, hazy, minute hazy patch become visible.

 

Saturday, May 14 : the sky was even worse. I used my SW Classic 250 P Dobsonian to see some double stars.

-While adjusting the finders ( RACI 8x50mm and Radiant 1x) on Zeta UMa, I noticed the star Sidus Ludoviciana to have a companion.

Did somebody know that star had any role in the story of the ''exo-planet'' of 1722 of Johann Liebknecht ?

-I split at 150x/ Mark III zoom eyepiece the double stars  STF 1495, STF 1544.

- At 480x , I observed and made a drawing of STT 235 which have a separation of 0.97''.

- 36 UMa or LDS 2863 is a very wide double star with a separation of about three minutes.

-I failed again at resolving Dubhe/ Alpha UMa or Bu 1077 AB. I saw again just AC, a binocular double.

-I recovered some motivation by reobserving Zeta Her at 300x/ Lacerta UWA 4mm+ Skyglow filter and Delta Cyg.

- The last object observed was the central star of NGC 6826 at 300x. 

Below is my drawing of STT 235 + ABT 8 AB/C , with some details. 

 

Clear sky, Mircea

 

 

 

 

Superb write-up and what sounds like great sessions. May I make a suggestion? Copy it into its own separate Obs Report so we can comment on the lots of interesting things you’ve said here…

Cheers, Magnus

I would second Charles Bracken's Astrophotography Sky Atlas. Although it doesn't feature doubles, it has just the right map size and scale for me to choose any of the other targets. Also the way it denotes the objects on the chart, PNs, Globulars, OCs, galaxies and of course nebulae is just right for me. And I'm not an astrophotographer, I'm purely visual.

Magnus

Just looked at more information about NGC 5053, a glob near M53. Now I understand why I couldn't find it; it's dimmer (mag 9.6) and spread across a larger area than NGC 2419 aka The Galactic Wanderer at mag 9.06. I have observed NGC 2419 through this scope, but it was extremely faint. With the non-perfect transparency of the other night no wonder I couldn't see NGC 5053. A challenge for the future.

Magnus

Since I've got into astronomy I've spent a lot of time at two very different places, different from a light-pollution viewpoint. One is 20 miles from central London, say Bortle 7/8. The other is about as far South West Ireland as you can get, nominally Bortle 3. I have an SQM-L meter, and have taken data readings on almost every possible clear night for the last 3 years or so. The attached graph shows this data plotted by SQM reading vs Sun altitude. The "upper limit" curves agree quite nicely with the lightpollutionmap.info Atlas-2015 modelled data, modelled from an observer's viewpoint based on the 2014 VIIRS satellite "look-down" intensity readings.

Magnus

In a run of grey, windy or excessively Moonlit weather recently an unexpected gap in forecast appeared, suggesting Wednesday night (18th May) might be clear. It was! Dark enough to start collimating by about 10:20 pm, Moonrise wasn’t due until 1am. I find the time of Full Moon counter-intuitive. You imagine that being a full Moon, you won’t get dark nights for ages yet. A full Moon means that as soon as the Sun sets, the Moon rises, being diametrically on the opposite side of Earth from where you’re standing. So what that means is that the next night, the Moon won’t rise until approximately an hour after sunset, and each day a further nearly-hour. So, at just 2-3 days after full Moon, I found myself with nearly 3 hours of full darkness to play with. That suddenness of dark nights after full Moon always surprises me.

Anyway, it was still a bit breezy from the South West so I set up on my more sheltered North-facing patio. Scope of choice tonight was my 300mm Orion-Helmerichs newt on AZ-EQ6 controlled by Nexus DSC. A quick collimation and alignment on Polaris and Arcturus. My novelty feature this night was First Light for my freshly centre-spotted 300mm mirror (Orion), which had been originally about 1mm off-centre, juuuust too much for my OCD to tolerate. I made up a triangular centre-spot and set it up so the apexes point directly to the collimation knobs. It allows me to predict which direction the Barlowed-return-shadow will travel.

Not having had much notice of the clear spell, and my perma-list of target objects being once again well out of date (I really need to create lists in advance), I cobbled together a short list, all in more or less the same area: the environs of Coma Berenices, mainly a mixture of galaxies and globulars. I did have one double on the list, WZ Cas (gleaned from, I think, @Nik271). Seeing was not bad except for some above-building regions, but transparency was not perfect: there was a sheen of high thin cloud, and a few instances where a thicker band moved in and luckily out again. Sky darkness started off at SQM-L 15.0 at 10:20 pm, where I could just barely discern Polaris, reached 21.65 just before 1 am, and when I packed up just after 1:30 am it was back down to 20.95 and sinking fast with the 89% Moon starting to rise. And, once again amazingly, no dew!

Mostly I used my Ethos 13, giving me 141x and a 0.7 degree field. I’d occasionally move up to the Delos 10 for 183x and did a bit of star-testing with the Delos 3.5 at a crazy 522x.

Anyway, the observing. I initially checked conditions on Epsilon Lyrae, the Double-Double, which was superb as it should be in a 300mm.

First on my list was a Coma galaxy, NGC 4872. At 11.7 mag, it’s one of the brighter members, or shall we say less-dim, of the Coma Supercluster. Certainly there was a galaxy fuzz-patch, and another slightly brighter one further East of it (below-left through the eyepiece), which would have been NGC 4889 (mag 11.4). There are dozens and dozens of others packed into that region, but I’ll need a bigger scope to see them in due course. It’ll be a treat when I do, Sky-Safari makes the field look like a globular of galaxies!

Next on my list was another Coma galaxy, NGC 4725. This was mag 10.0, much brighter, and so it was through the eyepiece. It’s more or less face on, with a bright core and a definite spiral structure, nicely symmetrical and clearly so with averted vision through the eyepiece. Lovely. Wikipedia’s photo of it is worth a visit, and I definitely “got” that shape.

Now I went to M64, assuming from memory it was a bright featureless elliptical, so I found it, took it in, moved on quickly. But on investigation it’s called the Black Eye Galaxy, and has interesting features that I might possibly have been able to discern had I spent more time on it. Dammit, next time.

My first globular of the evening was not in Coma but not far away, M13 in Hercules. Oh my God. I’d had a recent superb view through my 200mm newt, but this was a view apart. So big and so bright. I’ve observed M13 many many times obviously, and have seen the Propeller before but fleetingly. Tonight the Propeller was obvious and prominent. I spent a reasonable length of time at M13, returning to it a couple of times too. Never tiring.

Another glob, this time in Coma, M53. A third of the size of M13 and less bright, but still well resolved. I tried upping the magnification from 141x to 183x, but it became less satisfying, a little too dim. There’s another glob nearby, NGC 5053, which for some reason I couldn’t find. Perhaps it’s too loose, more like an OC, so I gave up. Certainly I think I should have been able to see it in this scope, but another time.

I chose M3 next, another large bright globular, not dissimilar to M13. I tried to study it and make out some features but by now patches of cloud were intruding, and from time to time it would disappear entirely!

I abandoned the Coma area and turned completely around to look at WZ Cas, a widely-spaced double in Cassiopeia, a random entrant to my list, but my goodness what beautiful colours! Deep red and bright blue, entrancing. No doubting where they were in the star field once you’re there! I finished off with Albireo and that was that. Cloud was now almost everywhere.

An entirely unexpected dark few hours and a few new objects. I used Charles Bracken’s “Astrophotography Sky Atlas” to select my list. It has just the right layout and scale for me to pick a page and choose targets. It doesn’t have any doubles, but for PNs, Galaxies and Clusters (and nebulae obviously) it’s very good. Thanks to @PeterW for introducing me to that.

Cheers, Magnus

Very nice indeed, I'm impressed. I've gone a similar route with 2 Newtonians now. One started life as a blue-tube Skywatcher 300p, the other as an Orion Optics VX8.

The SW now has an Orion primary, a Hubble Optics secondary, a Helmerichs tube and a Steeltrack focuser. Only the SW primary cell and spider remain. I plan to design and build my own primary cell as its inferiority to the rest of the set-up now really bothers me, for example the 6 radially-spaced and far-too-short M4 cell-tube attachment bolts are inadequate, and one has stripped its thread, so really there are only 5.

The VX8 now has a Helmerichs tube and Steeltrack focuser. The original Orion 8" primary cell is I think quite good and the spider is fine too. The secondary is 63mm which is too big for my visual use so I plan to get a Zen 50mm (as you suggested from another post ).

They are both a utter pleasure to use though, I had the 300 out last night. I can feel your joy in making the very best of what has clearly become a really fine instrument.

Magnus

Thanks Stu I’ll draft up a paragraph to fit in before that section

2 hours ago, retroformat said:

Dear Magnus, thanks for your excellent report.  I have the exact same telescope as yours, and will soon undertake a disassembly to look for what I hypothesize is an off-center primary mirror assembly (due to bent collimation screws/threads in the rear cell/plate... and all of that due to a side impact on the OTA).  But I have a question/concern.  Your excellent pictures give a good idea of how everything is held together.  For example, it is evident that the entire primary mirror assembly, along with the rear plate, is held onto the OTA with only the collimation screws.  And you give warnings about that as well.  Your pictures also suggest that the only thing holding the primary mirror/outer baffle onto the rear plate is... the focus threaded rod.  This threaded rod moves the primary back and forth upon the inner baffle, the mirror being free to slide upon that central baffle, but held in check only by the focussing rod.  Yet in your disassembly instructions, you non-challantly have us remove the "brass focussing assembly (ACW) all the off (perhaps 20+ turns!)"   From your pictures, it looks like this would completely free up the primary mirror, so that it would then slide down the inner baffle, and fall onto the corrector plate.  I am obviously missing something... what am I missing?  Is a step missing prior to step 8.?

What's not clear from the pictures is that there is an O-ring sitting in a groove on the inner baffle tube precisely to stop the outer baffle tube (and primary) going past a certain point and coming off. I do refer to it in step 15, but you're right it should be mentioned it earlier by suggesting that one checks if it's actually there. Unfortunately that post is too old now for me to edit, though I shall edit it on the version on my website.

Good luck with your repair.

Magnus

On 12/05/2022 at 21:00, Dan_Paris said:

In Europe, there are two excellent choices :

• Romano Zen  (http://lnx.costruzioniottichezen.com/joomla/index.php?option=com_content&view=section&id=26&Itemid=28)
•  Mirro-sphere (http://www.mirro-sphere.com/miroir-plan-ellptique.html)

I have one set of newtonian optics from Romano, very good quality, reasonable prices and short lead times. Franck Grière (Mirro-sphere) has an excellent reputation too.

 

Of all these options the only one that suits is the 47.5mm Zen secondary. The others are either too small or too big. 47.5mm is right on the small limit for me, but just about inside my window. Unfortunately it's not clear from their website how I go about actually ordering one, but I'll admit my understanding of Italian is not good! Can anyone help me howto make an order?

Thanks, Magnus

1 hour ago, Ags said:

If I can't get excited about a 90 mm f5.5 fluorite doublet that weighs 2 kgs and disassembles like an 1970s movie assassin's rifle, exactly under what circumstances should I get excited? 🤣

That reminds me. I must re-read Day of the Jackal

Indeed. I looked for it just the other day and found it still there to my surprise. I should’ve mentioned it. 

One scope in that corner especially with a wooden tripod looks very Galilean. I cannot imagine for a moment that it had gone unnoticed, but I can imagine that Mrs Stu wasn’t going to admit she approved even though she probably did. But two? With a carbon tripod? Playing with fire…

@markse68 @Dan_Paris thank you … exactly the information I was looking for. Between those I will certainly get sorted.

Magnus

I have a need for a high-quality secondary mirror of 48-50mm minor axis. It’s to replace the current 63mm one I have on my 200mm scope. Aside from the obvious UK optical outfit, whom I’d prefer not to trouble with my business, are there any other convenient, say, UK sources?

I did buy a high quality 70mm Hubble Optics from astroshop.eu last year which now adorns my 300mm, but that took 5 months to arrive.

Or perhaps someone has a VX8 or CT8 with a 50mm and would like to swap up to my 63mm for AP purposes? Win all round.

Cheers, Magnus

Crikey they didn’t keep us waiting long did they! There’s a slightly more extensive account here 

https://phys.org/news/2022-05-astronomers-reveal-image-black-hole.html

My last observing report was First Light with my Orion/Helmerichs 200mm, which while enjoyable and Moon-down was characterized by my inability to get my wider eyepieces to focus: my light cone wasn’t poking far enough outside the tube. I’d been limited to 100x magnification and higher only, with my Delos 10 and up just about able to make it.

This time, I’d given each of the 3 collimation screws 3-4 full turns ACW each, pushing the primary mirror an extra few crucial millimetres further up the tube, pushing the focal plane out by the same amount. It worked. The first eyepiece I used for rough Alignment was my Nagler 31, apparently notorious for its out-focus requirement: amongst the very “worst” out there. So I won’t need to drill any more holes further up the tube to re-site the primary’s cell unless I want to attach a camera, for which I have no plans.

For mounting for tonight’s session I decided to go for total overkill and mount the 8.5kg OTA on my AZ-EQ6, the only driven mount I have here, and to use it with the standard SynScan handset. I have a much more capable Nexus DSC, but I wanted to stay familiar with the SynScan.

After rough alignment on Polaris and Arcturus, I pointed my N31’s 2.5 degree field and 32x mag at the Double Cluster, NGC 869. Why it isn’t a Messier object I don’t know. With a 30% Moon and the Sun only 13 degrees down it was still between Nautical and Astro Twilight, so the view was quite bright. Nonetheless beautiful, both clusters in one field at slightly beyond my maximum exit pupil. I revisited it later at better darkness (21.4 IIRC) but at only 20-odd degrees elevation and above one of my distant light-domes, so it was still quite bright.

I also revisited the Cat’s Eye Nebula, NGC 6543, which I failed to find last session, just to confirm I could see it but didn’t bother upping the magnification for a closer look. Another time for a dedicated PN session, I think.

Next was M81 & M82, which were nice in the wide field, but I remember thinking the view was definitely inferior to my 12”. I would normally have had the option of using my OO/H 12” for a night like this, but it’s been in bits lately while I’ve been re-centre-spotting its primary mirror, besides tonight was specifically for the 8”.

I put in my Delos 10, upping my 32x to 100x, and did my “Izar check”. A bit wobbly, but definitely a double with clear space, and I moved on to Eps Lyrae, also nicely defined all round, but not as crisp as at First Light.

Like last time, I moved on to M13, with the Delos 6 for 145x, and the view was astounding. This night was far from perfect seeing, but the transparency was extremely good. My meter for example showed 21.4+ at zenith steadily through the night after Astro Twilight despite the 30% Moon being still well up. Back to M13, though. The view was as good as I can remember, better than for First Light, with stars peppering all the way to the centre. Even hints of the Propeller. I have seen M13 regularly through my 12” and recall being mightily impressed, and impressing others, and have definitively also seen the Propeller through it. But somehow tonight’s 8” view seemed amazing, even considering reduced 8” expectations. I now cannot wait to get my 12” out again, maybe even alongside the 8” to do a real-time comparison.

With Cygnus high enough to be worthwhile, I had a quick look at Albireo: blue/yellow lovely as ever. Not a patch on Almach obviously ;), but still worthy of its name “Jewel of the Sky”.

I put the Nagler 31 back in and selected Sadr, the middle star of Cygnus. I wanted to browse around the star-fields. It was entrancing, with obvious patches of dark nebula too. The first time I’ve really done this actually, as I’ve only recently had a wide-field option out here.

I finished on the Moon, it was a seething wobbly mess. It was directly above Schull a few km distant, and I must have been looking through heat plumes in that direction.

All in all I’m now more than happy with my nearly-finished 8” f/4.4. It has a 1/10 Orion mirror in an Orion CNC cell. The Helmerichs tube is supremely stiff. The focuser is a Baader Diamond Steeltrack with the absolute minimum out-focus I can get away with (about 75-80mm). Its centre-spot has been repositioned to exactly the right place. I don’t feel a finder-scope is necessary for such a fast small scope, so I’ve allocated it one of my Baader Sky Surfer Vs. The only serious modification left to do is to get myself a 48mm or 50mm secondary to reduce the CO to 25% or less; currently it sports a 63mm (CO 31.5%, far too much for my taste). And the rest is essentially cosmetic: I’ll replace all the cheap Orion cross-head fittings with Torx or Hex from accu.co.uk: secondary collimation-screws, primary-cell fixing bolts; finder-shoe bolts.

Thanks for reading.

Magnus.

PS couldn't resist adding a shot I took with the camera on the tripod in the pic at the start

On 07/05/2022 at 09:54, Zermelo said:

… In my case, the wifi password is a 33-character string of random letters, numbers and symbols, so it's a bit of a pain. I suspect I'm an outlier.

In the general population you’re probably right. On here I'm not so sure. Mine is a mere 28 random characters 😁

Christ you said expensive but I wasn’t expecting that! £45 ish for 100ml. But I’m still tempted.

M