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Old 23-05-2008, 09:12 AM
你B
Its only a column of dust

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Location: New Iceland
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observation report 23/5

Well I woke up at 3:30am for a dunny stop and noticed it was clear outside. I decided to try my luck on Jupiter. Everything was in my favour - no jetstream, a big high and perfectly still, cold air. Weather charts painted a scenario that anyone would drool over. Seeing as it was early morning, all concrete surfaces should not be radiating heat by now.

I noticed that the scope was out of collimation, probably due to the cumulative effects of rising and dropping temps over the course of a month - a direct symptom of melbourne's crap climate.

After around 50 minutes of cooling I got started. Didn't take long to be met with dissapointment. Only in melbourne is the seeing still crap even when everything is in your favour. And its true. Sydney, Adelaide and even Tasmania have been getting awesome seeing. Like with everything else climatically good, Melbourne misses out. :chair: Normally this wouldn't be a big deal coz I'd just do some DSO observing, but the blazing moon meant that the planets and globulars were the only viable targets - the 2 classes of objects most affected by seeing.

Anyway, now that I was out there, cursing this damn climate, i figured I'll try and get something out of it.

Scope: 10" GSO dob
Seeing: 3/10 (which is bleedin AWESOME by Melbourne standards. :bat

Jupiter
156x was pushing it. Like seriously. And the thing is directly overhead. Unbelievable. Everything appeared just washed out. i've never actaully seen the moons as what they should be - a tiny disk. It was the usual blurry, smeared mess. Nontheless, I did get some decent detail happening. Numerous festoons could be seen with relative ease. I also got numerous white ovals among the festoons. The GRS was visible. In the SEB, a lot of white features could be seen, they looked like ovals or perhaps gaps between streamers connecting the two rifts in the SEB. Then, my mum turned on the heater and the outlet which belts out all the heat is stratigically placed in my backyard. Then all hell broke lose, in terms of seeing.

Also tried to hunt down a few DSOs with Sky Atlas 2000 and a fogged up finder.

M15
This is the Pegasus globular but at 142x, I could barely see anything. I could make some resolution but it was impossible to achieve the required mags to really bring it out. Seeing no doubt was killing it.

47 Tuc
Already surprisingly high. A stark contrast to M15. There's no competition.

NGC 55
Managed to find it with great difficulty (fogged up finder) but at 73x there was a long streak - should be excellent on a moonless night. I haven't actually viewed this with my 10 or 12" scopes.

All in all, an ordinary session. Oh and my scope's mirrors fogged up upon return into the house. Doesn't appear to be any major dew spots left behind.

A few notes....
Last time I was outside, all the objects that were setting were overhead. It has been so cloudy here for so friggin long, that former morning objects are now sinking in the west. The Virgo area was below the horizon, even though the last time i had a nice long session, it was still in the east at midnight. Scorpius was behind my roof. Yet last time I was battling morning twilight while chasing the goodies in its sting.

What have I learned from this morning?
Well....Melbourne's climate sucks
Mornings are now prime time for galaxies
Scorpius/Sag are now evening objects
Don't turn on the heater.
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  #2  
Old 23-05-2008, 08:25 PM
ngcles's Avatar
ngcles
The Observologist

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Join Date: Dec 2006
Location: Billimari, NSW Central West
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The only crap seeing is in Melbourne?

Hi 你B,

Nice report as usual, wow you were up late -- M15 indeed!

I'm certain Sydney can be every bit as frustrating seeing-wise as Melbourne. In my estimation, only 1 night in 20 here is better than merely "good" and a lot of 'em are poor let me tell you.

The other thing is that the larger a telescope is, the more seeing sensitive it tends to be. Larger apertures produce a smaller airy-disc. If the seeing is worse than the size of the disc, it will _look_ worse than if you were using a smaller 'scope that produces a larger airy-disc.

M15 will resolve pretty well in your 'scope, in the right conditions. Dark sky + good seeing, though the planetary nebula within it (Pease 1) is likely just beyond a 12".

Good skies will come -- patience grasshopper!

Best,

Les D
Contributing Editor
AS&T
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