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A memorable dark sky tour with a 20" dob and binoculars+OIII/Hb


Ships and Stars

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Hi all,

Not the most detailed report, but a fairly incredible whirlwind (er...literally), non-stop session last night from 9pm to 3:30am. I've cut and pasted some of this as I'm dog-tired and owe my wife for putting the kids to bed last night, so computer time is limited at the moment.

Really went for it last night, was very clear here in the NE of Scotland. Set up the 20" dob at 9pm on a hilltop at my dark sky 'B' spot, around 450m @21.80SQM. It takes a bit of work to load and set this big scope up, but to me, the views from a dark site are worth every calorie used to get it there! And some people buy a gym membership instead...🤣

GOTO was working a treat, took extra care on the levelling, alignment and centring alignment stars carefully to eyepiece - used an 8mm plossl to centre, seems to make a big difference over my typical semi-sloppy 'that'll do' alignment with a wide angle EP.  

Don't even know where to start with the observations... 

Caught B33/IC434 Horsehead early to test seeing/transparency, it was immediately and directly visible with the 17.5mm Morpheus and Hb before my eyes even fully dark adapted. A good sign and the more you see the HH, the easier it gets when the conditions agree. I've even caught it with my 300p from this site. Then up to Flame Nebula, down to M42, and in no particular order, Heart and Soul, lots of dispersed nebulosity here.

Then Auriga with IC405, IC410 on each side of the 'Auriga Ladder' (see pic below), a quick label I came up with a few days ago for the double row of stars that separate IC410 and 405 - by the way, the 'ladder' was easily visible with the naked eye last night. (update - this asterism already is officially known by some as the 'flying minnow') Surprisingly, I also noted a very bright nebulous circular patch about the same size as IC410 a fair bit north of these but still in Auriga. I was still trying to figure out that one until this morning. The first answer based on my very brief description: Spider and Fly - thanks Gerry! The other possible though less likely contender Stephan mentioned is SH2-232, don't think many of the Sharpless catalogue objects are normally visible with binoculars, but using filters on good bins under dark skies might work here.

Viewed these with both the scope and binoculars using OIII & Hb, my preferred bino filter choices. The widefield view through the binos was especially good.

Excellent view of California Nebula with the 15x70s Apollos and Hb/OIII combo, first time I've seen it so clearly though the binoculars. This would be one for mounting the bins on a tripod and spending some time. I think you would need both filters on binoculars to see it, it's amazing how the brain combines the two different levels of brightness and contrast and picks the best of both. 

Back to the dob and M38, M36, NGC1907, NGC1893, M1 Crab Nebula, Pleiades, Double Cluster, Hind's Variable Nebula (amazing, looks like a comet, first view of that one), IC2162 (was going for Lower's Nebula, but got sidetracked - is Lower's Hb filter or OIII anyone?), IC 443 Jellyfish (very nice, a first on that). Some favs revisited - M108 Surfboard Galaxy, Owl PN.

Then there was the Rosette...

First time I've seen the Rosette, yes, first time. Holy smokes, sort of like a condensed version of the Veil, but seemed even brighter. Just stunning! And the circularity, just amazing. Going back to that one soon I hope.

Went into the Caldwell Catalogue a bit more Cave Nebula, got all sorts with that one, seems very complex. Crescent Nebula,  Eskimo PN (excellent), C59/NGC 3242 Ghost of Jupiter PN, just brilliant, very low on horizon. Cat's Eye nebula. I think that's it, left my sheet in the van!

Then the galaxies... good grief. Just kept the 21 Ethos in the focuser to take it all in. 

Leo Triplet, Leo Quartet, over to M95, 96, 105 and the NGCs immediately to the north and then, over to Markarian's Chain and environs, first time there, another holy smokes moments with some audible gasping. I lost count at this point and was literally talking out loud to myself. Kind of like Bill Murray in Caddyshack if he was an amateur astronomer. Dozens of galaxies and I didn't even sweep the whole area. Head was spinning. Bright ones, faint ones, very faint ones showing just a slight whisper, side on, flat, you name it. Galaxies everywhere. Just mind-blowing. 

I certainly saw a lot of objects due to the GOTO. I know it's not a race, but the reason I didn't spend more time on each one was the wind. The vibrations from the gusts frequently made very detailed higher mag observations impossible. It was gusting steadily past 30mph for most of the night and was about -2C I reckon without windchill, so I would take in a few objects, hop in the van for a sip of coffee, pick some more from my list, and hop back out...

I left the light shroud off the truss dob all night just to reduce windage, I simply wouldn't have been able to view with it on even with the van acting as a windblock, and there was always a chance it would pull the scope over. 

Wind was picking up considerably by this point and the scope was vibrating way to much to concentrate on anything in great detail, so I called it a night...

My top 5 to revisit from last night:

1.) Markarian's Chain

2.) Rosette Nebula 

3.) Hind's Variable Nebula

4.) Spider and Fly

5.) California Nebula

Scratch that, I'd like to see them all again...

PS I find using binoculars, especially with filters, under dark conditions complements the big dob and offers a lot of bang for the buck, as they say. You can take in some amazing widefield views, and the way the brain combines the same image using different filters for each eye is very interesting. 

Anyway, I'm beat! Thanks to everyone who has suggested DSOs by the way and advice on EPs and technique here on SGL, I'd be lost without. Good luck and happy observing all 👍

 

Auriga Ladder.jpg

Edited by Ships and Stars
added pic of the 'ladder' aka flying minnow asterism
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18 minutes ago, Charles Kirk said:

Great report.

Thanks for posting.

I think that you would have a chance of seeing the pulsar at the heart of the Crab Nebula with your 20 if you like a little challenge.

Thanks Charles, to me the Crab is usually just a relatively faint 'puff' even in a decent sized scope, but was showing quite strong last night. I tried to tease some detail out of it but the windy conditions prevented perfectly still views. I didn't know about the pulsar? I'll definitely look for that next time.

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18 minutes ago, Paul M said:

Excellent report and what a session!!

Remind me, what scope is that?

Thanks Paul! The dob is a SW Stargate 500p with goto. I was only able to get my grubby paws on it because I was working lots of extra hours at the time (last March) and it came up for sale unused as the original owner could not use it due to health. It's transportable for a night out, but requires a small van ideally. In all, it's around 75-80kg I'd guess, but the two heaviest parts are around 32-35kg each. Not too hard to set up if you've done it a few times. I don't have to use a ladder, just an 8-10" step lets me view comfortably at zenith. A great scope. 

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9 minutes ago, Ships and Stars said:

The dob is a SW Stargate 500p with goto.

Ah, yes just found your "first light" post.

Funnily enough, when I Googled "SW Stargate 500p with goto", the search returned some images of a young Donald Sutherland :)

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31 minutes ago, Paul M said:

Ah, yes just found your "first light" post.

Funnily enough, when I Googled "SW Stargate 500p with goto", the search returned some images of a young Donald Sutherland :)

My 'first light' post was fairly uninspiring, think I said something profound like 'stars of all magnitudes were visible'. That was the first time I'd ever looked through a reflector and only had a 60mm refractor for a few weeks as a child before it broke. I was amazed that such a simple design using only two mirrors could produce such an image, let alone a sharp one. I didn't know enough objects in the sky at the time to even use a finderscope, think that was March or April last year. Never even tried the goto until August (the infamous midge attack/observing session in the Highlands)...

Edited by Ships and Stars
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Great report. Nothing beats a big dob under dark skies.

The "Auriga Ladder" you found is already well known as the asterism "Flying Minnow", and can be made out without optical aids in a decent dark night easily. A description can be found in this comprehensive compilation of asterisms (pg. 11):

http://deepsky.waarnemen.com/asterisms/Asterisms_EN_VER4.2.pdf

Optically more pleasing is this:

http://www.deep-sky.co.uk/asterisms.htm

Enjoy!

Stephan

 

Edited by Nyctimene
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1 hour ago, Nyctimene said:

Great report. Nothing beats a big dob under dark skies.

The "Auriga Ladder" you found is already well known as the asterism "Flying Minnow", and can be made out without optical aids in a decent dark night easily. A description can be found in this comprehensive compilation of asterisms.

Thanks Stephan! I thought I'd created a new asterism but suspected someone had likely beaten me to it, probably a very, very long time ago. I've just read both links on the flying minnow, very interesting and these are perfect for binoculars. Thanks again.

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PS - @jetstream and Stephan, after another look last night, I'm fairly certain now I did not see Sh2-232 with the binoculars, it was indeed the Spider and another patch of apparent nebulosity I saw to the north was actually M38 the Starfish Cluster (doh), it looked like it has a cloud of nebulosity around it but with an OIII and Hb filter on, I couldn't resolve any of the stars. Don't know if there is any reflection nebulosity associated with M38, but it certainly looked like it. My fault for not having my star atlas handy, but it would have blown away that night! I saw the Spider again last night with the binoculars clearly, but nothing around Sh2-232. I will try for both the Spider and the Fly again tomorrow night. Clear but too windy for the scope. Again...  

Edited by Ships and Stars
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10 hours ago, Barry-W-Fenner said:

Great write up SAS.

Very productive evening with the big Dob. Out of interest what bortle was the sky you observed from.

Regards

Baz

 

Thanks Baz, always fun using that scope once it's set up, though I normally forget the finderscope or a step!

The LP map shows my B site on the dark end of Bortle 3, 21.79 with 37 μcd/m2 artificial light according to 2015 data.

Altitude is around 450m which helps, I could even see some cloud inversion last time I was there as it'a not terribly far from the NE coast. There is quite a bit of LP on the eastern horizon of the site from a town 15 miles away until around 11pm-midnight, but not nearly enough to stop play by any means.

By 2am (when I'm generally leaving) it's brilliant. The transparency there seems better than the LP ratings suggest, maybe it's the bump in altitude making a slight difference as the land to the east is flat pretty much right to the sea. 

There's my darker 21.92 A spot I sometimes go to, a solid Bortle 2 about 50 miles inland, but it's a bit of a drive unless I'm assured a really clear night. That's a great site when it's clear all night and I camp near there in the summer too.

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On 19/02/2020 at 00:19, Geoff Barnes said:

And I thought my session the other night under perfect conditions was good but it pales rather feebly compared to yours, I feel exhausted just reading it, superb!

 

I wish the wind had died down a bit, I could have kept going a bit longer. Was still quite tired though. I try to pack it all in when I can!

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On 19/02/2020 at 07:43, bish said:

Great report.  Big dob, dark  sky, good transparency, quality eps - does it get any better?

I'd love to take a magic transporter to the top of La Palma with the dob, or somewhere in the Nevada desert/Western Australia, but maybe I'm being unreasonable now 🤣

I do suffer from severe aperture fever, but think the 20" is as big as I'd really care to transport on a regular basis. Packs quite a punch for the moderate effort involved in setting it up. 

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10 hours ago, Ships and Stars said:

I'd love to take a magic transporter to the top of La Palma with the dob, or somewhere in the Nevada desert/Western Australia, but maybe I'm being unreasonable now 🤣

I do suffer from severe aperture fever, but think the 20" is as big as I'd really care to transport on a regular basis. Packs quite a punch for the moderate effort involved in setting it up. 

Atacama maybe ?😁

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