Peak District Star Party – Riverdale Campsite
Saturday 25th March 2017
7pm to 11pm No moon
M51 (The Whirlpool Galaxy) and NGC 5195
It’s been my ambition for 20 years to see the spiral arms of a galaxy, and I finally got the opportunity to take my 16 inch Dob to a dark sky site last Saturday. Shortly after arriving I asked a guy with a big Dob which galaxy is the best bet. As I suspected, the answer he gave was M51.
I trained my scope on M51, and as usual, I could see this galaxy plus the fainter galaxy, NGC 5195 underneath. Where I live, in town, I can see the bright core of M51, and the dimmer outer regions, but I can’t see any detail. I was very much hoping things would be different in the Peak District.
By mid-evening I could see that the outer region definitely looked brighter in some places than in others. I found that 150x magnification showed more detail than lower magnification. As I moved away from the core, downwards and to the right, there was quite a dark area, then a brighter area as I moved further way from the core. But I couldn’t piece the lighter and darker areas into a spiral. By 10.30, however, I was confident I could see at least a little piece of a spiral. The most obvious part started on the right of the core then swept down and round to the left underneath the core. There was also a hint of one on the opposite side. I decided that if I could work out from my own observations which way the spiral arms went round, then I would conclude I’d really seen them. After finding some sketches on the internet when I got home I decided that this in fact was the case, so I’m counting the expedition as a success.
As you might imagine, most other things looked a little more impressive, particularly M3, the globular star cluster just above Bootes in Canes Venatici. The most noticeable difference was the Owl Nebula. In the past I’ve only been able to see this using a light pollution filter, but it was clearly visible through the main scope without a filter in the darker sky. I still couldn’t see the eyes though. Unfortunately I could still only see the usual four galaxies in the Virgo Galaxy Cluster, M84, M86, NGC 4338 and 4435. Maybe I’d have seen more on another night or if I’d stopped latter.
22 inch Dob and 13mm Ethos eyepiece
I had a look at M51 through an 18 inch Dob, and then a 22 inch Dob. I could see a bit more detail in each, but not masses more. It’s the same when moving from a 10 inch to a 16 inch. There’s a worthwhile improvement in what you see, but not as much as you might expect.
Interestingly, both guys were using 13mm Ethos eyepieces, which would give them around 150x magnification. The opportunity to look through a really big Dob and an Ethos eyepiece made the trip doubly worthwhile. I have to say though, that I wasn’t sufficiently awed by the 100 degree apparent field of view that I’m going to buy one. Nor would a larger telescope be practical given how I store and transport my scope.
The one thing missing
The one thing missing from this event was the car loads of locals who’d travelled up to see the wonders of the universe and take advantage of the clear sky and fabulous telescopes. There weren’t any regular campers who wanted a look either. I did, however, notice that the campsite bar and café were jam packed with people. Shame. At least some people benefitted from the experience. I enjoyed myself. Even my girlfriend said she enjoyed the evening. Praise indeed!