A session full of DSOs: 23/24 Sept 2011

[michael.h.f.wilkinson]

Last weekend the weather was clear, so after Friday evening ballroom lessons, I hauled out the C8 (near midnight) and started stargazing until the small hours. The sky was quite clear, but a little high haze was present, which gradually became worse.

I aligned the 70mm finder with the scope on Vega, and first port of call had to be M57. The ring was fabulous as ever. I decided to confirm two objects I got for the first time only a few nights ago: NGC 6939 and NGC 6946 (Caldwell 12) in Cepheus. Both were a bit clearer than last time round. The former is a very nice open cluster, the latter a face-on spiral, very low in surface brightness (quite a bit harder than M101, closer to IC 342 (Caldwell 5)). A faint, blotchy shape was visible in averted vision, and I think I spotted the core.

I decided to browse through some unknowns in Cepheus, as it was near zenith, and least affected by the slight haze.

On my way to several Caldwells and Herschels, I noticed NGC 7235, a nice open cluster near epsilon Cephei, small but quite easy in the C8.

NGC 7380, a Herschel 400 object was close by, a cluster with associated nebula. The cluster was evident in both the 40mm and 22mm EPs. The quite extensive nebula was better with UHC filter.

Sh2-155, Caldwell 9 was the next target. This one really gave me a hard time. I switched EPs many times, inserted UHC filter, checked the atlas again, re-checked position, and finally, as my eyes became accustomed to the dark, using the 40mm Paragon and UHC filter, I saw why it was called the "Cave nebula": the cave showed up clearly. I have had this before with extended nebula: the dust-lanes give the nebula away, because there is often no clear boundary between bright nebula and surroundings, but there is a sharp edge between dust lane and nebula. Once you have found it, the cave s quite a nice sight. Not on a par with the brighter Messier nebulae, but it was certainly satisfying after a long hunt. After bouncing through the garden (quietly) and checking and rechecking the view, it was time to move on.

M52 was close by, so I gave it a quick look. It is a very nice sight in the C8, a near circular formation of stars, easily spotted in the star fields of Cassiopeia. A good reason for going there is that it is a good vantage point to find the next object:

NGC 7635, Caldwell 11, or the Bubble Nebula. This too required very careful observing. After checking the star atlas, I really needed time to let my eyes adapt to the dark again. After many attempts, a hazy patch appeared in the view, using the 22mm Nagler plus UHC filter. Averted vision only.

I tried getting NGC 7139, a mag 13 planetary in Cepheus, but no luck.

On the trail of Caldwells, I tried NGC 891, Caldwell 23 in Andromeda, but it did not show up. I know I am in the right area, and it should be in the FOV, but the light pollution towards the east prevented me from spotting it.

Leaving DSOs aside for a while, I had a look at Jupiter. Brilliant as ever (there goes my dark adaptation ), both equatorial bands showed detail, and all moons were present and ready for inspection. The seeing was not great, 254x was clearly too much, and even 203x was pushing it seeing-wise. So, back to DSOs.

NGC 7814 (Caldwell 43) was quite easy by comparison with the previous objects. A small fuzzy patch was readily spotted in averted vision, with hints of some structure. This merits a revisit in a really dark location. Nearby NGC 7479 (Caldwell 44) proved elusive.

Moving back to Andromeda, I had a look (as you must) at M31, M32, and M110. I could fit all three in the FOV of the 40mm, with some care. This sight never ceases to impress me.

Upwards, NGC 185, Caldwell 18, and another satellite of mighty M31 was fairly easy in averted vision. After checking the atlas again, I decided to hunt for NGC 147, Caldwell 17. I have tried and failed to find this object several times, but my earlier success with other, low-surface-brightness objects encouraged me. Of course, a UHC filter is no help here, so I simply alternated the 40 and 22mm EPs, scoured the area, when suddenly, in averted vision a very faint elliptical haze, with a slightly blotchy appearance, became visible. It is hard to pick up in the star field, and one of the hardest Caldwells to date (despite being mag 9.3). All the northernmost 22 Caldwells are now complete .

As it was close to 3 AM, I decided to pack the scope. I hae had evenings with bigger hauls of new stuff, but almost all the new objects were a struggle, and finding them is all the more satisfying.

[Nexus 6]

another excellent report Michael, the count continues, always a fine feeling to see something for the first time and worth a dance around the garden

thank you for the details on some unfamiliar objects

[swamp thing]

Great report with some fine studies in.

Thanks for sharing.

Regards Steve

[Skylook123]

Nicely done, as usual, Michael. Thank you for taking us along, and encouraging us to get out there and join the adventure.

Regarding Jupiter and night vision, you might try a neutral density lunar filter. I have found that during opposition seasons as this is, when we are relatively closer than conjunction times, a lunar filter significantly knocks down the glare and I can get finer detail to my eye.

Keep hunting!

[asteria]

I enjoyed your report. Thanks for writing this up and sharing it with us. All the best. Ed

[Moonshane]

Fab report Michael. Europeans are so much more refined that us Brits. How many of us have got our scopes out after a ballroom dancing lesson! Interest to hear you detected the Bubble in an 8" scope. Must try this with my 16" at a forthcoming star party.

[bish]

Looks like you had a great session. Well done on seeing the bubble neb. I may give it ago with my 10" from a dark site.

[michael.h.f.wilkinson]

Thanks for that guys. The Bubble was very hard, and I spotted only some of the more contrasty wisps, along with a bit of background. There seemed to be a comparatively bright linear structure near one star, and it was not glare or anything, because it showed up much more clearly in the UHC filter, whereas glare should be stronger without. I think I needed all 32 years of observing experience to spot this one. The fact that it was near zenith helped as well. I doubt that inexperienced observers would have spotted it. The longer you look, the more you see, as they say.

It was an exceptionally good session. I allowed myself a tot of malt whisky as the dew on the optics dried up before storing the equipment.

[Hypernova]

Quite a feat on viewing the bubble, I was always under the impression that it would be an imaging-only target for those of us not blessed with darks skies and/or large aperture 'scopes. I must give it a try when I get the chance as I have the dob with the same aperture as yourself, UHC filter and mag 4.5 skies on a good night.

The galaxy NGC 891 has always eluded me on even the darkest of nigths with the 8", no matter how much I get myself dark adapted I cannot see an hint of it at all, averted vision or not. Is it really meant to be such a tricky object to view visually or am I just not looking hard enough? I keep expecting to at least see a long thin smudge but I see nothing when I have the 'scope pointed in the right area

[michael.h.f.wilkinson]

Quite a feat on viewing the bubble, I was always under the impression that it would be an imaging-only target for those of us not blessed with darks skies and/or large aperture 'scopes. I must give it a try when I get the chance as I have the dob with the same aperture as yourself, UHC filter and mag 4.5 skies on a good night.

I think I had mag 5.0-5.5 skies at least that evening, especially near zenith. I must stress I only spotted one or two of the brighter strands of the Bubble, and only by using every trick I know, plus the new one of checking whether the diffuse nebulosity I saw was glare or not, but comparing the views with and without UHC filter. Glare should reduce with UHC, because the relative brightnesses of stars and glare remain the the same. Thus, because stars are reduced in brightness in UHC filters, glare reduces. By contrast, emission nebulae become relatively brighter. In this case, what looked like glare became apparently stronger with UHC, so must be nebula. Still, a very very difficult object, which instantly caused about of aperture fever.

The galaxy NGC 891 has always eluded me on even the darkest of nigths with the 8", no matter how much I get myself dark adapted I cannot see an hint of it at all, averted vision or not. Is it really meant to be such a tricky object to view visually or am I just not looking hard enough? I keep expecting to at least see a long thin smudge but I see nothing when I have the 'scope pointed in the right area

NGC 891 plagued me for a long time, and requires very dark skies, and lots of patience. I spotted it again yesterday, from my parents' place outside of town. I even caught glimpses of the dust lane, as the centre part seemed to appear as two stripes in averted vision. Those thinking NGC 891 is like NGC 4565, as they may seeing beautiful images on the web are in for an unpleasant surprise. Very difficult oject indeed. Finding he right area is not that hard, but spotting it is problematic with an 8"

[assasincz]

Wonderful report there Michael! Seems like it was a night to deserve our silent envy