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Scaraveen Observing, and a Lovely Clean Mirror Again! 20th April 2023 - OH300


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I’ve recently learned that here In the West of Ireland, there’s an in-between month that bears a resemblance to Harry Potter’s Platform 9¾, called “Scaraveen” (an anglicization of garbh mí na gcuach, obviously). It translates as “the rough month of the Cuckoo”, runs from approximately mid-April to mid-May, and is characterized by unpredictable squally weather coinciding with the arrival of said bird. To date, it’s been accurate on both counts: I heard my first Cuckoo of the season a few days ago, and we’ve had this bloody bitter East wind for ever, it seems.

So it was with surprise that Thursday, a very rough day weather-wise with that nasty Easterly wind, was due to calm right down and to clear up to reveal clear evening skies. We were “out” that night, but quite early, and sure enough when we got back around 10pm the sky was clear, there was only a little wind, and it was evident that Transparency was unusually good. By the time I’d finished observing around 2am, my SQM-L measured 21.9 . There was no dew at all.

If you read my previous report from a few days earlier (Stellarvue saves the day, or somesuch) you’ll be aware that I’ve been less than fully happy with my 12” mirror lately. Lacklustre, dull views for which I’ve suspected the primary of dewing up prematurely, but in fact I think the real culprit was a layer of extremely fine dust on the primary, aside from the normal dust I’m used to seeing and ignoring. Whenever recently I’d look down the tube with my headtorch, there’d be a grey-blue milkiness that I’d not noticed before – it was that that had caused me to abandon the other night it in favour of my 140mm refractor. So on Tuesday I removed the mirror (no small task with the otherwise superb OO cells) and cleaned it, and sure enough there was a dirt layer the like of which I’ve only encountered once before (on a SW 200p I bought that looked as though it had been exhaled on for years by a smoker).

I cleaned it my usual way it by swooshing in warm water, soaking in for a while in warm detergented water, then used the fingertip method with detergent, finally rinsing in distilled water and drying. On subsequent inspection, the fine dust was mostly STILL THERE. I repeated the whole process with similar (null) results. Finally, after testing on a small section near the centre, I used swabs of kitchen towel and a solution of household ammonia to mop the mirror, and that worked! The sight of the “clean lanes” forming when dragging the swabs was quite satisfying.

And “in the field”, what a difference! Looking down the tube with the headtorch was a totally different experience from before, and through the eyepiece suddenly the stars were high-contrast, sparkly and prominently diffraction-spiked again. Hurrah.

So, to the observing. I used my Nexus DSC to control the AZ-EQ6, and for once the Nexus performed without any glitch. After alignment at 100x, I only used two eyepieces for the whole night: my Nagler 31 giving me 59x and 1.4 degrees, and my Delos 10 giving me 183x.

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Recall that in my few-days-prior session I had abandoned the 12” owing specifically to terrible dim views of the Leo Triplet Doublet, and that my 140 refractor saved the day by providing immediately-following superb views of the Triplet. Naturally, therefore, M65/M66/NGC3628 was to be my first target for tonight. Wow. The SV’s view had been very good, but from this 12”, it was as much better as it should have been at such a dark site. What a change from the dirty mirror.

I decided that the first part of my session would include all the crowd-pleasing objects, that had looked so good through the ‘frac. So I moved on to M51, and this time I did actually say “Wow” out loud. So much detail, the obvious spirality and the cores so bright.

This mount set-up allows me to get the tube perfectly vertical if necessary, so M81/82 was next, and the difference again especially on M82 was obvious. Mottling along its length and that diagonal shadow-gap. Superb.

Not especially a crowd-pleaser, but I wanted to see what M101 looked like, as I recall being underwhelmed before by M101 even through this scope. I regard M101 as a more difficult version of M33, face-on and extended as it is. Well, even at 183x the core was obvious, even if the galaxy itself was larger than my field of view. Even so, faint mottled shading was evident as I panned across. I put in the Nagler 31 to triple my field of view and max out my eye’s pupil (5mm), and sure enough it was actually an impressive object in its own right. Before, it’s been enough simply to detect it. There was a bright core and extended shading, and perhaps with a bit of imagination, spirality. Rather pleased, actually.

So, obviously, my next target had to be what’s become my Nemesis: IC 342, the Hidden Galaxy. I like to think of this as a yet more difficult member of an M33, M101 progression. Suffice to say, it remains my Nemesis. Not a sausage, either through the Nag 31 or the Delos 10 or even through my 15x56 Zeiss bins. It’s possible I was looking in the wrong place, but all my GoTo’s so far had been on target, and even a 1.4 degree field hadn’t shown it to me. And this night was a highly transparent 21.9 night by the end, so I’m puzzled.

Anyway, for some reason I selected M102 next, although I was not familiar with it. As yes, as I type, I remember. I had been perusing SkySafari on my phone trying to ascertain the star-patterns near IC342, and I noticed one of my “Observing List” objects on the App was an object called “Spindle Galaxy”, aka M102. I found it, but didn’t know to look for its eponymous-ness (the dark dust stripe along its centre). Next time.

I had wanted to see some Coma galaxy-cluster members, and headed over to that area. I did find, I think, NGC 4889, one of the less-dim ones at magnitude 12.9 (!), and panning around there were tantalizing hints of smudges all over the place. I need a bigger scope for this area.

Markarian’s Chain beckoned now, the second time this season, and M84, M86, and the various other bright members did not disappoint, at either 59x or 183x. I fancy I saw more detail in the galaxies than the last time I pointed this 12” at them a few weeks ago: the cleaner mirror and/or better transparency no doubt. Also M87 nearby plus plenty of other dimmer galaxies around.

I was thinking about packing in now, so I intended to finish off with Epsilon Lyrae to check the seeing. At the time of first slewing, I was only at 31x. I sort-of-nearly was able to split them at that low power, but the view was more disappointing than I was expecting. It was only when I swapped in my Delos 10 and saw, before re-focusing, the out-of-focus diffraction disc that I realized the problem: the star “discs” were in fact D-shaped. I was mostly observing the corner wall of my house! Idiot.

On the point of dismantling, I suddenly noticed Hercules and realized that I haven’t observed a globular of any description for months. Rejuvenated, I went to M13 and reminded myself why it truly is one of the magnificent objects in our sky. Utterly, jaw-droppingly impressive. I spent quite a while on it, then moved a little to M92. Also hugely interesting. I returned to M13 and remembered that you can’t see M13 an not try to get its little companion, the galaxy NGC 6207. I found it, and was surprised to notice both a core and a nebulous elliptical haze, a completeness to it that I can’t recall having noticed before in this scope.

And now, finally, 2am, after four hours, it was time to call it a very worthwhile night.

Thanks for reading, Magnus.

Edited by Captain Scarlet
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Hi Magnus, thanks for your interesting observations report. This drives home the importance of clean optics!

Speaking of which, I need to start planning on cleaning my mirror soon, which I'm yet to do nearly three years into owning it. Wishing you clear skies.

Joe

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20 hours ago, Captain Scarlet said:

So I moved on to M51, and this time I did actually say “Wow” out loud. So much detail, the obvious spirality and the cores so bright.

Excellent report Magnus!

I too need to have a clean mirror and find that it does make a real difference. Great observation of M51, this one can just keep the glow increasing with the arms buried in it. Breaking them out like you did is very rewarding. A 12" newt is perhaps the best all round size scope there is- nice choice. Its focal length vs image scale and brightness will punch way above its weight.

20 hours ago, Captain Scarlet said:

I went to M13 and reminded myself why it truly is one of the magnificent objects in our sky.

What a great gift M13 is!  The "Propeller" feature is simply amazing to me and many refer to it as the Mercedes symbol.

 

20 hours ago, Captain Scarlet said:

I regard M101 as a more difficult version of M33

M101 is tough... not to see but to get it to reveal its delicate off center arms. The dob mob years ago were pros at this one seeing HII regions in the arms. I find that much practise can be needed to get the most out of this one and usehighly value my 100 deg eyepieces for it. Maybe there really is something to Al Naglers "Majesty Factor"? One slip in the mag/FOV on M101 and the arms will be lost IMHO.

Speaking of M33... I can see it naked eye- with difficulty. I have a hard time with the Bortle scale and it has a lot to do with its description of skies needed to see it... Even from very dark skies its difficult IMHO.

20 hours ago, Captain Scarlet said:

Markarian’s Chain beckoned now, the second time this season

Another unbelievably good series of galaxies. I'm a 'chain" counter- how many did you get?  There are a couple of tough elusive galaxies floating around the neighborhood that are always worth trying to see in averted. Here, the Chain is always the launching point for "vacuuming up" galaxies.

Great observing Magnus!!

Your skies are superbly dark and many more fine sessions await you- there is so much to see up there. Your 12" will reveal the oddball ARPs and Hicksons.  Eagerly waiting your report on Hickson 55 a super favourite, my 15" gets 4 of them and your 12" will show at least 3 but probably 4. Mind you there is a trick to seeing them... :grin:

Edited by jetstream
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