10th October 2012 - Ever Diminishing Returns

[Double Kick Drum]

A clear but 'nothing to write home about' type of sky was good enough to warrant a session but my expectations were not high. The Milky Way was barely detectable and the feintest star in Ursa Minor occasionally flickered out of view. A good 0.5 or 0.6 of a magnitude from perfect (for my back garden).

First up were a couple of small planetary nebulae. NGC 6803 in Aquila proved harder to star hop to than I imagined. It was easy enough to see but at four arc seconds looked stellar. Similar but slightly feinter was NGC 6879 over the border in Sagitta. An easy star hop from Gamma Sagittae, through 13 and on to 15 and just beyond. Both of these need a bit more aperture and magnification to be viewed with any detail.

North again to Vulpecula and another easy star hop to NGC 6802, an open cluster at one end of the Coathanger. The cluster forms an equilateral triangle with two feint pairs of stars at the Eastern end of the Coathanger. Given its magnitude and surface brightness (8.8 and 11 respectively), I expected it to be quite condensed but was dissappointed to find it nothing more than a soft glow, barely detectable.

The globular cluster NGC 7006 (Caldwell 42) in Delphinus was perhaps the pick of an obscure bunch. This again, is quite easy to find, just East of the head of the dolphin. Initially, I struggled to see anything but a prolonged stint at the eyepiece showed a circular haze with averted vision and the core was just visible directly.

I was unable to detect the galaxy NGC 7814 despite being certain I was in the right area. This is very close to one of the four main stars of Pegasus and so given a clearer night, I should be able to see this in the future without wasting much time locating it again.

Last up was NGC 2300, another galaxy close to Polaris but just inside the realm of Cepheus. I couldn't see it conclusively with the 15mm eyepiece and speculatively moved up to the X-Cel 8mm. The extra contrast more than compensated for the extra magnification (79x) and I found it reasonably easy with averted vision. The nearby galaxy NGC 2276 proved too feint for my equipment / ever ageing peepers.

As I gradually exhaust the list of DSOs I have set myself, the likelihood is I will have to move onto some sketches. It is nice finding more difficult objects but they are getting ever less rewarding to view. I just need to sort out a comfy seat.

__________________________________________________ ______

Observing Session: Wednesday 10th October 2012, 20:00 hrs to 22:10 hrs BST

VLM at Zenith: 4.9 to 5.0

New - Revisited - Failed

[cotterless45]

Lovely report, good to see what is possible in less than ideal conditions.

There's quite a lot in "Job's coffin" (Delphinus) in addition to the lovely gamma double.

NGC6891 and 6405 are two planetary nebulae, there's another globular NGC6394 and the galaxy NGC6971.

This is how the very remote and captured from another galaxy NGC7007 it looks in a Dob ;http://www.perezmedia.net/beltofvenus/archives/001446.html

Awaiting clear sky here and the forthcoming PSP,

Nick.

[michael.h.f.wilkinson]

Nice report again DKD. NGC 7814 requires really good conditions, as I recall. I found NGC 6803 very hard, not because it is faint, but because it is almost stellar. Nearby NGC 6804 is way easier, because it is quite a bit larger. I have had a shot at NGC 6879 but got confused in the rich star field (I should have printed out finder charts from Stellarium). I am quite surprised you managed that, it is listed as mag 13 (these listings are not always accurate) and is only 7" across, well done. I haven't bagged either NGC 6802 (on the todo list) and NGC 2300 yet (hadn't considered this yet, but I will now).

Nick, I trust you mean NGC 6905 (planetary, the Blue Flash Nebula) and NGC 6934 (globular). I haven't checked out NGC 6971 yet, but then that is mag13.8, so probably even beyond my 8" scope (let alone DKD's 5").

[rory]

got a fair bit covered in a two hour session dkd. i missed quite a few objects in delphinus due to going on the book i was useing only referenced two objects (ngc6934,and a double star at 12gamma) i shall have to do my homework more thoroughly in future. as a globular fan ive noted ngc7006 for my next session,whenever that will be !

great report.

[m_j_lyons]

Good night looking for some small/faint targets - I find PN more difficult than faint fuzzies most of the time because they often appear so stellar. NGC7814 was pretty faint when I eye-balled it over the weekend - mag 11.6 with a surface brightness below that - a pretty good challenge if light pollution is a problem.

Do you subscribe to Sky & Telescope? If I remember correctly NGC 2300 and NGC 2276 were listed in the Deep Sky section as worthy targets available nearly all year long.

Happy hunting.

[Double Kick Drum]

Lovely report, good to see what is possible in less than ideal conditions.

There's quite a lot in "Job's coffin" (Delphinus) in addition to the lovely gamma double.

NGC6891 and 6405 are two planetary nebulae, there's another globular NGC6394 and the galaxy NGC6971.

This is how the very remote and captured from another galaxy NGC7007 it looks in a Dob ;http://www.perezmedi...ves/001446.html

Awaiting clear sky here and the forthcoming PSP,

Nick.

Luckily, non-ideal conditions for me are still better than urban / suburban skies. I guess I shouldn't moan too much!

Only NGC 7006 could be seen directly and the two planetaries just looked like stars and could only be confirmed due to being placed in recognisable asterisms. NGC 6891 was better to look at as was the nice glob NGC 6934.

[Double Kick Drum]

Nice report again DKD. NGC 7814 requires really good conditions, as I recall. I found NGC 6803 very hard, not because it is faint, but because it is almost stellar. Nearby NGC 6804 is way easier, because it is quite a bit larger. I have had a shot at NGC 6879 but got confused in the rich star field (I should have printed out finder charts from Stellarium). I am quite surprised you managed that, it is listed as mag 13 (these listings are not always accurate) and is only 7" across, well done. I haven't bagged either NGC 6802 (on the todo list) and NGC 2300 yet (hadn't considered this yet, but I will now).

Nick, I trust you mean NGC 6905 (planetary, the Blue Flash Nebula) and NGC 6934 (globular). I haven't checked out NGC 6971 yet, but then that is mag13.8, so probably even beyond my 8" scope (let alone DKD's 5").

When reading up, I noticed variances in quoted magnitudes and size were quite large on NGC 6879 and NGC 6803, depending on the information source. CdC quoted both as mag. 11.0 and surface brightness of approximately 7. Although both stellar in appearance, I found NGC 6803 looked a bit brighter than mag. 11 and NGC 6879 seemed just beyond mag. 11. Measurements varied from 4.5 arc seconds up to 7 arc seconds.

I don't usually attempt any fuzzy beyond mag. 11.5 and only higher surface brightness objects beyond mag. 10.5 as a rule of thumb.

[Double Kick Drum]

got a fair bit covered in a two hour session dkd. i missed quite a few objects in delphinus due to going on the book i was useing only referenced two objects (ngc6934,and a double star at 12gamma) i shall have to do my homework more thoroughly in future. as a globular fan ive noted ngc7006 for my next session,whenever that will be !

great report.

NGC 6934 is probably the easiest DSO to view in Delphinus. NGC 7006 is feinter but still reasonably within the limit of my scope and definitely worth a go. NGC 6891, mentioned by Cotterless, is a good target too.

Happy hunting!

[Double Kick Drum]

Good night looking for some small/faint targets - I find PN more difficult than faint fuzzies most of the time because they often appear so stellar. NGC7814 was pretty faint when I eye-balled it over the weekend - mag 11.6 with a surface brightness below that - a pretty good challenge if light pollution is a problem.

Do you subscribe to Sky & Telescope? If I remember correctly NGC 2300 and NGC 2276 were listed in the Deep Sky section as worthy targets available nearly all year long.

Happy hunting.

I am not a S&T subscriber but did think that it was an all-year target. Only problem being so near Polaris was the initial manual scope movement whilst using the finder. Equatorial mounts are a bit like shopping trolleys in that area of the sky and don't move the way you want them to!

[michael.h.f.wilkinson]

When reading up, I noticed variances in quoted magnitudes and size were quite large on NGC 6879 and NGC 6803, depending on the information source. CdC quoted both as mag. 11.0 and surface brightness of approximately 7. Although both stellar in appearance, I found NGC 6803 looked a bit brighter than mag. 11 and NGC 6879 seemed just beyond mag. 11. Measurements varied from 4.5 arc seconds up to 7 arc seconds.

I don't usually attempt any fuzzy beyond mag. 11.5 and only higher surface brightness objects beyond mag. 10.5 as a rule of thumb.

I often find planetaries are seem brighter than their listings. I wonder if this is due to their line emission spectra. There may be a bit of a mismatch between the spectral sensitivity of the retina, and that of the equipment used to measure which may account for this.

[rory]

having seen uranus for the first time a few nights back ,i can now understand where planetary nebulas get their names.

[michael.h.f.wilkinson]

I understand the phrase was coined by William Herschel, and the likeness of many PNs to Uranus and Neptune is striking.

[cotterless45]

Good to show beginners. I usually pick pns out by their colour, especially if you defocus.They seem to stand out more in the refractor, whether this is background contrast or not.

Even better is the direct disappearance/blinking/flashing, always goes down well!

Just corrected my map; NGC6934 and 6905, must be getting new specs!

Nick.

[michael.h.f.wilkinson]

Good to show beginners. I usually pick pns out by their colour, especially if you defocus.They seem to stand out more in the refractor, whether this is background contrast or not.

Even better is the direct disappearance/blinking/flashing, always goes down well!

Just corrected my map; NGC6934 and 6905, must be getting new specs!

Nick.

If you look carefully, stars of low magnitude also blink, so this does not separate stellar PN from fainter stars. A much surer way to confirm a sighting is by inserting a UHC or O-III filter and looking for stellar object which do not fade as much as proper stars. I sometimes wonder if a simple grating in the EP to show stellar spectra would work to detect PN. I wonder if anybody has tried that.

[rory]

found ngc 7006, faint circular haze. didnt bother with much else the conditions were murky.even m31 looked poor !

[Double Kick Drum]

found ngc 7006, faint circular haze. didnt bother with much else the conditions were murky.even m31 looked poor !

Yeah, it started ok but got hazy and wispy cloud rolled in. Congrats on bagging another Caldwell.

PS like the avatar, Dan.......Dan............Dan...............Dan............Dan.............Dan, just when you thought this'll end now................Dan..............Dan - genius!

[rory]

ha, didnt even know it is a caldwell ! i really need to get my act together.

(i just didnt get alan .p when i first watched it.now i just think its utter class )

[popeye85]

Thought I would just revive a old topic for this question as doesn't really seem worthwhile starting a new one! 

I'm keen to get a sight of ncg 2300-is it possible in a 8"dob? If so what should I expect and any tips? 

Thanks 

Popeye.

 

 

[Paz]

According to the interstellarium atlas it's doablewith an 8 inch scope.

I've seen it (only ngc2300) under light polluted skies with a 14". It took averted vision to find it at first but it was (just) visible directly once I had realised I had it.

I think dark skies with an 8" would give a better show than light polluted skies and a 14".

[popeye85]

Cheers-looking forward to trying to find it! I'm heading up to Skye next week for a few days ago use going to use that fantastic opportunity to get some really faint objects under my belt but Murphy's law has decided that It is to be full moon while I'm there!! Hey ho!