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A Tale of Two Telescopes - Wednesday April 13th


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The 90% moon was already high and bright before sunset and the prospect of an extra day off on Thursday offered the chance for a good long session with the "new" 10" Dob. 

I set up to cool whilst it was still light, first parking the car over the road, giving me better clearance and sightlines from the least light infested part of the back yard.   The first task was this new collimation business.

I'm now fairly sure I've got the secondary well positioned and used the now-fixed Astro Essentials laser to collimate, delivering almost perfect circles on Capella, still quite high over the rooves to the W.   I attempted to get this perfect adjusting just from the star test and managed to mess it right up again. Went back to square one with the laser and this time the result was very close to perfect, if collimation is like tuning an instrument then this was "good enough for jazz" as the muso phrase goes... (Many thanks to @Pixies @malc-c @Spile for all your help de-mystifying this for me, definitely getting there!). 

So to the moon in stunning detail. I am thrilled by the resolution of 10" - so many more craters and craterlets, rilles become much more commonplace and tiny shadow details, for example, although Sinus Iridium was fully lit, there was a tiny dark shadow cast by Promontory Heraclides that I am not sure I would otherwise have picked up. As others noted, the Valis Schroteri, Aristarchus, Heroditus , Montes Harbinger region looked superb, crisp & 3D with deep shadows.   The Baader Mk IV Zoom seems a great tool in this scope, giving 156x in normal mode which was about the useful limit in the early evening's slightly swimmy seeing. I did experiment with the 2.2.5x Barlow however which turns the zoom into a 10.7 - 3.5mm zoom - up to 357x, which although messy tonight was still well illuminated and focusable, boding well for future rock-steady seeing nights. 

With that great big thing shining away, it was clearly not a night for the galaxies - although I spent a good while trying to get M81/2 in the finder, struggling a bit with the elevation and unfamiliar dob-nudging technique. Gave up and went for some clusters instead - despite the moon and being low in not the best part of the sky from my garden, the Double Cluster looked superb, such a dense core in the more Northerly cluster and huge depth of stars resolved. Can't wait to look at this with this 'scope on a dark night when well positioned!

I was using a 31mm Baader Hyperion Apsheric for finding purposes giving a whopping (to Mak users) 1.79 degrees and despite there being noticeable edge-coma the immersive view in the 2" eyepiece was nevertheless lovely.   One difference from the Mak & refractors was that I ditched the Baader Neodymium filter that I love and routinely use in those 'scopes, here in the Newt it was giving a blue tinge that looked odd, better without. 

A quick check in on M36,37 & 38 - all showing more stars than I am used to but not as good as a few nights ago when I enjoyed some moonless time with them. 

On to the Beehive and more struggles with aiming the Dob near the moon with very little in the way of reference stars visible, dropping the Telrad half way between Castor and Algieba and hunting around. I went and fetched the 10x50s from inside and this helped me get this in the field and I spent a long time drifting in space enjoying the depth of the view.   

Having achieved what I set out to do Dob-wise, much improved collimation adjusted in the field, and enjoyed some stunning views of the moon and clusters, I decided to give my neck and back a rest and have a lazy GoTo tour of some doubles with the Mak 127.  It was late by now and seeing, whilst not perfect had definitely improved to a slow phasing with four or five still seconds at a time. 

All that collimation fiddling makes aligning the GoTo properly on the Mak seem a breeze, so I really took my time levelling the scope and using the Zoom's 188x to carefully centre Capella and Arcturus.   As a result was able to land perfectly on:  

Castor, revelling in the perfect tight, bright diffraction rings. Then the Sapphire & Gold of Iota Cancri (an Albireo challenger in my opinon).  Bathed in the glow of Algieba's golden headlights. Porrima, a relatively easy split at 150x of an offset, even white pair.  

Having great fun by this time and enjoying standing and the ease of use of a small scope on a tall tripod (complete with wine eyepiece tray), I spent a good while on Izar. Couldn't split it at first but upped the power to 150x with the Baader Zoom and watched the white secondary pop out of the first diffraction ring - adding more power pulled this out and I got the best and reasonably steady view at around 250x with the zoom/barlow combo.  I watched this for ages - thankful for the tracking mount on this 0.25 degree field of view.  

Had a good long look at M3 whilst waiting for Vega to pull out of the light extinction to my North East.  At this point was missing the aperture of the Dob but still a nice view, and M13 even more so, definitely glittery and one of my favourite objects in any 'scope. 

Epsilon Lyrae - The Double Double, split from around 100x and up delivering a fine, well separated view at 225x (Baader Classic Ortho 10mm, 2.25x Barlow).  The BCOs work brilliantly with the 2.25 Barlow for the Zoom, with the added advantage that it raises the viewing position on them to a point where banging my head on the Telrad is less of a thing...

Finished with a cracking view of the Ring Nebula M57 - a tiny, crisp smoke-ring in space. 

The best of both worlds tonight, long deep views with the 10" and the fun of crisp double-splitting with the convenience of GoTo & tracking in a moonwashed sky(Bring on new moon with that big Dob though..)  

Best of all, no work the following morning! 






















Edited by SuburbanMak
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  • SuburbanMak changed the title to A Tale of Two Telescopes - Wednesday April 13th

Nice report Mark!👍

Two very different scopes and clearly with different core strengths, sounds like you have the best of both worlds..

Thanks for a good read this evening while the almost full moon is convincing me it's not worth getting the scope out tonight..that, and the fact I'm literally exhausted after spending all week refurbishing/rebuilding our garden ponds!😱😊.


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