Thursday, 2 September 2010

Observing 1st September 2010

The long-term forecast is not looking too clever for the autumn (if it was the Mess Met Office I would not believe it, but it's The Weather Outlook, who got this year's dismal summer spot on) so I'm going to fit in as much observing as I can until the weather breaks up.
I am also doing the Herschel II at the same time as the H400 and, looking at the list of them, I have already seen quite a few. Inevitable really, as I've been doing deep sky observing since 1993. However, my observing sessions always previously took the form of ambling round whichever constellation caught my eye at the time and I never really did a structured observing program in the past, so my observations are scattered around various note books and sketch pads, so I need to hunt them out and see what I have and haven't seen. Still, re-observing things is not going to be a chore - although quite a few Herschel II objects not being plotted on Sky Atlas 2000.0 is a nuisance.

Date: 1st September 2010
Conditions: Slightly chilly, no wind. Quite a lot of dew.
Transparency: III but better at zenith (II). Mostly clear except from some high cloud. Jupiter bloated with halo, however, the sky was good at zenith.
Seeing: I, very steady
NELM: 6.1 (a little skyglow reflecting from high clouds)
Instrument: 12" f/5 dobsonian with 22mm Televue Panoptic (69x), 15mm Televue Plossl (101x), 11mm Televue Plossl (138x), 8mm Televue Radian (190x), UHC and OIII filters.

NGC 6800, open cluster in Vulpecula - Large, loose irregular group of stars forming a distorted loop. Moderately faint. 15 brighter stars plus a load of fainter stars. Not rich. 69x.

NGC 6723, open cluster in Vulpecula - Not plotted on my Pocket Sky Atlas or Sky Atlas 2000.0, so I used the Night Sky Observers' Guide Vol 2 to find its position and plotted it myself on both atlases. I really need to start using my Uranometrias more - in fact I am planning to buy the second edition for use while observing and keeping the old ones on the book shelves.
It's easy to find 6723 once you know where it is. It's in a rich field, more or less halfway between α Vulpeculae and Cr 399. Faint and small. Not rich. Triangle of stars (10th/11th magnitude) at the centre help identify the cluster. 69x, 101x

At this point a neighbour across the way put his garden light on, so his dog could see while it was going about its 'evening constitutional'. I'd not seen this light before, or not noticed it (the reason being, our garden's very large and what happens the other end of it is not always noticed from the house or patio; the patio was my previous observing place), but it was badly aligned and blitzed my observing area. I think I'll be asking him if he can adjust it in future, if it's trespassing then it's aligned incorrectly.. After 15 minutes, I was wondering just how long it takes for a dog to have a pee (our dogs are in and out in two minutes!) when the light, thankfully, went off. These are the same neighbours who don't have curtains on their upstairs windows, no doubt believing themselves unseen (uh uh, no you're not!). If ever I win the lottery, I'm moving somewhere where I don't have neighbours! Why are the general public so obsessed with lighting everywhere up?

Ok, now the irritating light's been turned off, back to the observing and it's time for some faint nebulae.

Sh 2-101, nebula in Cygnus - near a double star, this is an area of faint nebulosity. I can't see it very well without a filter, but the UHC brings it out nicely. It's a large irregular patch with dark lanes in it. 69x, UHC

NGC 6888, emission nebula in Cygnus - Located among a conspicuous group of five stars, this can be seen without a filter, but only just. A UHC filter brings out the crescent shape nicely but an OIII isn't much of an improvement. With each filter there are hints of more extensive nebulosity to the north east of the crescent. the SW portion of the nebula is the brightest and the SE portion of the crescent is a bit fainter. 69x, UHC, OIII

Minkowski 92 (M1-92), (planetary?) nebula in Cygnus - This looks like a faint double star at low power but is obviously non-stellar at higher power. One 'star' is larger and brighter than the other and they are very close together. 69x, 101x, 138x, 190x.

I packed up at midnight, as the high clouds were moving in and it was getting mistier.

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