Nature of Australian Jet Stream?

[John Hothersall]

Hello just after some experience, although I am not a newcomer to imaging we have just emigrated to Cleveland-Brisbane from UK in April.

I image deep space/lunar/planetary and am just setting up mount and scope after our shipping arrived undamaged thankfully.

In UK we have JetStream somewhere near or over us but did not think it would be a problem in Oz but since April JetStream has been over us continuously sometimes strong sometimes weak. Is this a Winter phenomenon?

What is the JetSream like over the year as it is very bad for planetary imaging.

Thanks JohnH.

[asimov]

Your in for some bad news I'm afraid. I'm not far north of you, been here 2 years. Last year I counted 5 occasions where the seeing was above 6/10. This year so far I've seen one night over 4/10.

I'm not sure if this is normal for QLD or not but I won't be sticking around much longer to find out.

DSO's:thumbsup: Planets:sadeyes::(

[John Hothersall]

Thanks - I think?

Tell me it cannot last forever, although today JS looks much better.

Regards, JohnH.

[gregbradley]

There is a jet stream map/forecast on the net. Sorry I don't have the link but try googling it.

Greg.

[Liz]

Hi John :hi: ... hope you are settling in Ok in beautiful Queensland. I remember you posting before you came over. :)
Glad your scope made it OK. ;)
Dont know too much about jetstream,and hopefully some of the guys will see your post and comment.

http://www.skippysky.com.au/Australia/

is a good site for weather, and does have a jetstream aspect.

[John Hothersall]

Thanks Liz, yes not a thing damaged on the long voyage to Oz from Dover and everything accounted for. My CCD's work fine my EQ6 mount slews great and it is setup and polar aligned ready for imaging.

Was going to try Venus in the West as I have never imaged this one before as it was too difficult from my location in the UK, but the JS has been hanging around, I have links to JS map now and hope it goes away so I can see how Venus looks in my new Astrodon UV filter.

Regards JohnH.

[asimov]

The jetstream is a weird beast. The JS can be right over the top of your place & yet you'll get a great planet capture, & then at other times according to the maps, it will be 200 KM south of you yet the seeing will be a 2/10 with all data recorded for that night deleted in disgust.

That's because there are 3 layers to contend with. The JS itself, mid & lower levels. It all depends on all threes interaction with one another. And then there are all these different types of seeing: Fast seeing/the seeing that involves big slow undulations of a planet/Seeing where the planet moves left & right 50 pixels rythmically - I could write a book on the subject! :rolleyes:

If you follow the maps religiously, you'll find yourself staying indoors for the night & basically missing out;)

The best idea that I've found after 6 years in this planet imaging game is to not let the maps (or predictors) fool you or put you off. Just get out there & pull the trigger every time it's clear & your'e available to do so. Eventually you'll get some nice captures.

To sum up on what I really mean: this Jupiter + Io transit was captured on the 13th July 2010 in fluctuating 1-8/10 seeing. I'd give it an AVERAGE of 4/10 however there was roughly 1000 frames from a total of 5000 frames that was 6-8/10 so I stacked 600 frames to be safe. Also played it smart & dropped back on my FL so this is at F15 rather than my standard F20-25 with the 11" SCT. I took 38 AVI's at my standard F & all of them got deleted after spending a whole day stacking, previewing etc.

There's not too many planet imagers in QLD & there's a reason for that, however If I'm going to be here I intend to make the most of it:D

Good luck:thumbsup: and I hope this helps:)

[John Hothersall]

Thanks John, I did not realise the JS was so complicated, I mostly image deep space but have been doing more planetary over past 18 months. I have seen the seeing alter over a couple of hours and know how different finished results can look with only 5 mins difference in capture time. Will certainly be giving it a try, UK was pretty miserable QLD may be the same will have to wait and see.

Regards, JohnH.

[asimov]

Well I prefer the less complicated version John. If it looks pretty stable naked eye then it's worth setting up for I think. Mind you steady conditions naked eye can equate to this fast seeing I was describing earlier. Hard to tell until the object is on screen, & that story tells all.

Good luck with your imaging John.