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An Impromptu Session in Shropshire


Swithin StCleeve
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When I arrived at my usual campsite in Shropshire on Monday night, I wasn’t actually expecting to do any astronomy as the forecast wasn’t great, but as I turned my engine off, and turned the van lights off, I was greeted by a wonderful clear sky, with the Milky Way stretching overhead. So without further ado, I set the dob up, (which takes thirty seconds, such is the genius of the dob design).
Here my dob at my site in the daytime.

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I find when I’m in the sticks, (my caravan is at a Bortle 4 site), the Telrad finder is mostly all I need these days. The 10X erecting finderscope I have alongside it is only really needed when I’m closer to town, and I can’t see the stars I’m hopping from. For these observations I used a 28mm eyepiece, unless I say otherwise. I don’t know the field of view, (I don’t even know the correct focal length of my scope, but you can see it’s quite long, about five foot). I find the 28mm fine for deep sky stuff.
So, with no plan in place, I started with M57, the Ring Nebula, and it was pleasingly bright. I often overlook M56 – a quite bright globular nearby. I remembered to check it out this night and it’s easily findable in a ‘line’ with stars to the left of the ‘squashed box’ of Lyra.
M71 next, and this is fast becoming one of my favourite globulars, probably because it looks so unlike a globula cluster. The 10” mirror really does it justice, but this is on Messier object that can be disappointing in small scopes I think, (note to self, look up what H20 is, it’s right by M71).
Just up to the left of Sagitta, I hopped to the easily findable dumbbell nebula. Very bright this evening and the ‘misty bow tie’ shape easily discernible.
Hercules was heading west, and I visited his two showpiece globular clusters, with M13 really burning brightly. I’ve only been using the 10” mirror for a few months, the previous five or six years I’ve been using an 8” Skywatcher, and in terms of gathering light, there is a very noticeable difference. Does anyone know how much more light a 10” mirror finds, when compared to an 8”? There must be a formula, (I'm rubbish at maths).
Saturn’s moons. Last time I had an observing session I made the mistake of not noting the time down when I made my sketch of the background 'stars'. I didn’t make that mistake this time. I sketched the planet, and every nearby point of light I could see, to check with Stellarium when I got back home, (which was a few days later).
I was pleased to see that along with Titan, I’d seen Rhea and Dione with the 15mm eyepiece. Dione was very much just on the verge of visibility. I had to use averted vison, and it only really appeared when the air steadied.
The Saturnian moon project is on-going. I wish I’d used a 9mm eyepiece now.
M31 was an easy naked-eye object, and I spent quite some time on M110 again. It’s quite bright when you get under a nice dark sky, and I’ve had several pleasing views of it this year.
M11, the Wild Duck cluster is always a treat. The duck I can see is different to how other people see it I think. But it’s such a bright pretty cluster, which you couldn't confuse with any other. It's easily found in the Scutum Star Cloud, (yea, I know it's all easily found if you use a go-to, but where's the fun in that?).
Yes, I'd insert a smiley there if |I used them.
Ursa Major was quite low, and I tried for M97 and M108 in the same field of view. I saw these together earlier in the summer and it was a real treat, but I couldn’t find a single deep-sky object in Ursa Major on this evening, and it was due to the constellation being low in the bright western sky. I couldn’t even find M51, (I didn’t try for Bodes). In fact,  after looking at Scutum, then turning the scope to Ursa Major, for a split-second  I thought something had gone wrong with my scope! Where have all the stars gone!
By this time Jupiter had appeared from behind a tree and all four Galilean moons could be seen, two on each side. Because I'd been trying to find galaxies in Ursa Major, the bright light of Jupiter was a bit of a shock to my eyeball.
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Up till now I hadn’t got my maps out, so I pulled out my Webb Deep Sky Society Star Atlas and looked at Hercules, which – although quite low, was certainly in a ‘sweet spot’ of dark sky. So I look at page eight and there’s a galaxy – NGC6207 -just above M13, (below in my scope). I wasn’t hopeful, because I have a splendid failure rate with NGC galaxies. But, there it was, and quite unmistakably bright. It looked to be ‘pointing’ to the great cluster, and when I re-checked my map, yes, it was a spiral, and pointing at M13. How had I never seen this before? I must have looked at the Great Cluster hundreds of times over the years. 
The Webb star atlas doesn’t give magnitudes, and I was off-line so the only way I could find the magnitude of this galaxy was to text an astro-buddy from the Wolverhampton Society.

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The text told me it was 10.08 mag, which is the Wikki version. I was somehow disappointed it wasn’t dimmer. I didn’t have my observing reference books with me, so it wasn’t till this afternoon I found James O’Meara has included this object in his Secret Deep book , (object 73). He puts it at 11.6, (‘a tiny spiral wonder hiding in the shadow of M13’). I have had conflicting magnitudes before, and whatever the magnitude is (I've also found mag 12.00 on-line, any advance on twelve?) – I think it’s one of the great secrets of the summer sky. A nd what a great reference point this would be, a test as to the darkness of the summer skies? Could it be seen in the true summer, when there is no astronomical darkness? I’m looking forward to finding out. Galaxy NGC6207 isn’t included in my Nortons 2000 by the way.
I spent more time with M31, trying to see some dust lanes, and trying to be honest enough with myself to admit – erm. . .no. But I did go back to my Webb book and check out anything ‘new’ for me to see there, and there’s a very large open cluster NGC752. This also has a Caldwell number – 28. And it’s a real treat! Overall mag 5.7, and in my 28mm eyepiece it sat beautifully in the field of view, filling the eyepiece. I’d say the stars are pretty similar in appearance, and evenly spaced. It made me very happy to add this cluster and the galaxy in Hercules to my observation list, and I look forward to visiting them again.
After about an hour and a half’s observing, I got cold (I wasn’t really dressed for observing), and hungry. And with the caravan heater on, I retired, about 9.45, with the Pleiades rising above the treeline, leading the way for Taurus, Orion and the winter promise of more deep sky treats in the coming months.

Edited by Swithin StCleeve
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Lovely report @Swithin StCleeve 👍

Nice setup you have there, very convenient for spending some time under dark skies.

I believe the Wild Duck cluster is so named because it looks like V formations of flying ducks. It took me a long time before I got that but I do see it now, more so at higher powers if I recall correctly.

Skysafari has NGC 6207 at mag 11.3, somewhere near Mr O’Meara. That’s one I’ve not seen before so will have a look out next time.

Info for Ha20 attached, and open clusters apparently.

 

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Great report, you got more clear sky than me on Monday night, but Shropshire is not a small county.

The propeller is I think, the name given to the three radial dark rifts about 120 deg apart, visibly discernible in the cluster. In this image they are located at about 6 o’clock.

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Very nice report, I enjoyed reading it.

To answer your question: a 10 inch dob will collect about 50% more light than an 8 inch. The formula is simple take the square of the ratio of the diameters, so (10/8)^2= 100/64= 1. 5625.

This will be noticeable if using the same magnification.  You should be able to see all the moons of Saturn of magnitude 11 or above, provided they are not too close to the planet: Rhea, Dione, Tethys, Titan of course, and Iapetus. Iapetus is quite far from Saturn so easy to confuse with a star.

Edited by Nik271
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Thanks Nik. I knew the 10" was a big leap from 8", but I didn't realise it was 50% more.
I wish I'd have gone to a higher power eyepiece for Saturn. Next time I will. Dione, as I say, was almost not there at all. It's like when you look at something, and your brain can play tricks and tell you that you've seen something you haven't. That's why I've decided to sketch what I see, and only later compare with any maps. Seeing a map first can put ideas in your head about what is really there.

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1 hour ago, Swithin StCleeve said:

 Seeing a map first can put ideas in your head about what is really there.

Indeed. Some of these moons only show up with averted vision and disappear when you stare at them too hard. 

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I was near Craven Arms, about three miles out, to the west. There are quite a few good camp sites round there that have dark skies. Anywhere near the Long Mynd area, or going towards Bishops Castle is good. 
If you're feeling adventurous, it's only an hours drive from there to the Elan Valley, which is a true dark sky site.  

The Wolverhampton Astronomical Society had its first observing weekend in this area of Shropshire (at a different site) last month.
 

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16 minutes ago, Swithin StCleeve said:

I was near Craven Arms, about three miles out, to the west. There are quite a few good camp sites round there that have dark skies. Anywhere near the Long Mynd area, or going towards Bishops Castle is good. 
If you're feeling adventurous, it's only an hours drive from there to the Elan Valley, which is a true dark sky site.  

The Wolverhampton Astronomical Society had its first observing weekend in this area of Shropshire (at a different site) last month.
 

47.jpg

Beautiful shot!

My family are farmers near Clun. Must take the scope up next time I visit!

Many thanks,

Tony

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29 minutes ago, Xgaze said:

Beautiful shot!

My family are farmers near Clun. Must take the scope up next time I visit!

Many thanks,

Tony

Lovely area. The Kangaroo Inn in Clun is a nice little pub. Parking in Ludlow on market day is a nightmare though. It's a shame we had a blanket of cloud for three nights the other week camping.

Great report Swithin StCleeve thanks. 👍

Edited by ScouseSpaceCadet
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