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Old 03-10-2007, 06:58 AM
你B
Its only a column of dust

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Exclamation does seeing affect DSO's? - YES IT DOES!

The first clear sky in days. It was a little windy but bloody hell I had an absolute gut full of Melbourne's cold and cloudy lame climate.

Although the temp fell well short of the forecast as usual, it was clear. I was soon to discover that the excitement will be short lived. I took the 10" outside and cooled it for a hour, altohugh both indoor and outdoor temps were similar.

Dropped in the 18mm Ultima for 69x and aimed the scope at the lagoon Nebula. Why can't I focus the stars down to pin points? I check my collimation, although in the dark its a bit difficult. Aiming the red light at the cheshire opening, it looks good. So what's going on? Let down, I turned to 47Tuc. At 69x, I could resolve stars almost all the way to the core. But at 166x, I couldn't even focus it. The focus just wouldn't "snap" - rather it was all 'mushy'. What the hell? This is what I'd expect at 400x or so. Not at 166x. My scope wasn't to blame, considering the views I got on a previous night. I suspect Melbourne's perpetually sensational seeing again.

I focused on Acherner at 166x and immediately confirmed my suspicions. At just 166x, the star was a fuzzy, flaring, bouncing, wavering mess. It would've been perhaps 1/4 the diameter of Jupiter. You could see the star's glare flickering in the eyepiece. Unfocusing the star, the disk was just boiling. Seeing would've been 1/10 on the pickering scale, and anyone who's seen the animated seeing scale, Acherner looked like the 1/10 or 2/10 examples.

Clearing it would be worthless staying out any longer. I just packed up and went in, ready for the next clear sky in 2-3 weeks time.
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Old 03-10-2007, 07:17 AM
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h0ughy (David)
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Thats the nature of the beast - why not go to a lower power and make the best of a bad situation?
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Old 03-10-2007, 07:18 AM
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rmcpb (Rob)
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Sure does as you found out. Just have to stick to low power on those nights, at least you are out getting some peaceful time by yourself............

Keep looking up
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Old 03-10-2007, 07:50 AM
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Nevyn
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Uglage??

You're not the only one! I've had my new scope for about four weeks now and the two clear nights I could use it the first night collimation was uglage (is this the right term?). So the next day I put in my order for a laser collimator. The day it arrived, by the time I worked out collimating the sky had clouded over again
Two nights ago the first best chance for a good night outside, 47Tuc looked magnificent but Jupiter just a blurred blob. M42 was almost as equally dissapointing but the Tarantula nebula looked a treat!
Both frustrating and fun at the same time, I had forgotten about the fires we have around the district at the moment.
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Old 03-10-2007, 07:53 AM
你B
Its only a column of dust

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uglage, fugly - both good terms to convey the rage

well the wind was picking up so I didn't really have a choice. The scope handled moderate gusts well but not long after I packed up it was a howling gale.

It was not an ideal night for observing at all. Shocking seeing and poor transparency, wind etc. We are overdue for one of those truly peaceful, clear calm nights with good transparency.

I also tried Jupiter last night. At 166x, I couldn't achieve focus at all. It was just a blurred fuzzball, couldn't even see the two major bands. I think we have a new record for poor seeing. Sure as hell never seen anything like it in my life. Infact, you could actually see 47Tuc fluttering slightly if you looked closely. Never seen a DSO flutter in the seeing before.

I looked at the Tarantula last night aswell and frankly it was nothing compared to the view I got in full moonlight last week.

Last edited by 你B; 03-10-2007 at 08:15 AM.
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Old 03-10-2007, 09:41 AM
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turbo_pascale (Rob)
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I was out in the roll off roof obs last night (1 week old barlow still yet to get a run in anger). Jupiter was a blurry disaster - I have to get it imaged by about 8:45 before it hides behind my house. By then the wind picked up and the shed was rattling around a little too much (the scope was getting buffetted inside!)

At least it wasn't cloudy

Turbo
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Old 03-10-2007, 10:16 AM
你B
Its only a column of dust

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"Blurry disaster" is right! Last night wouldn't support anything above 50x on any object - be it planet or DSO. I mean, stars looked like tiny fuzzballs at only 69x. If I can't get good focus at 69x, something is very wrong. Absolute shocker. Seeing this bad would almost certainly be as rare as 10/10 conditions.
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Old 03-10-2007, 11:07 AM
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PhilW
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seeing

I had the same experience last night. I have never seen stars look so non-stellar - I don't think I have ever had worse seeing. And Jupiter was just a boiling blob. So I gave up & watched TV.

Phil
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Old 03-10-2007, 11:19 AM
DougAdams
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30 minutes with 10x50 binoculars for me at midnight.

Looked at M31 (almost invisible large smudge). Tried to find M15, but couldn't. I'm sure I starhopped correctly - top left star of the square of Pegasus, bunny hop in a curving arc and it should be right where it wasn't. Quick glance up, 47 Tuc was naked eye, so I must have been lost. I was looking back towards Melbourne, and it was awash with light pollution.

Fixed some rattly spouting at 1am (it was blowing last night) and went to bed.
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Old 03-10-2007, 11:23 AM
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rmcpb (Rob)
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It seems as thought the jet stream has found a way to ground level here for the past week
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  #11  
Old 03-10-2007, 11:29 AM
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l was trying to do some imaging last night and could hardly see a guide star due to the bad conditions. the stars are just a faint blob through the f/10 and it gets worse when you factor in the light from the reticle.
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