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Norfolk star gazer

Finally Seen Jupiters Grs

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Up at 4.30 this morning on a mission to see the GRS. Only a few thin clouds about, but a big bank of thick cloud heading in from the south.

Freezing cold and dew formed very quickly. Had a quick hunt around to get my eyes adapted, but so cold that I nearly gave up. Focused my attention on Jupiter and tried a selection of EPs and barlows (trying to find the right magnification for when the spot appeared). Found 240 sharp but small image and 480 about the right size, but magnification to high for much detail. At about 6am I had a couple of minutes at 480 when the image was so sharp that I could make out a lot of detail and thought it would be a great view when it appeared - then the thick clouds rolled in. They cleared by 7, by which point the sky was lighter and the dew was turning to ice and I was constantly wiping the EP and viewfinder (even with a dew shield on it)

I saw the spot long enough to say that I've seen it and will probably wait now until it's in the early evening sky before I attempt that again

Edited by Norfolk star gazer
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Lovely sight, always worth watching Jupiter for moon transits, shadows and the grs,

Nick.

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Nice one, always good to see. x480 is very high, and with practice I think you will find that you will see more detail at lower mags due to the better contrast and less seeing turbulence.

Looks like the GRS will be transiting again at 3.16am Monday morning if it's clear!

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Nice one, always good to see. x480 is very high, and with practice I think you will find that you will see more detail at lower mags due to the better contrast and less seeing turbulence.

Looks like the GRS will be transiting again at 3.16am Monday morning if it's clear!

I believe that it transits about every 10 hours, so will try and plan a late evening viewing.

480 was a nice size to view, but you are right about the contrast and turbulence. 240 was nice and sharp, just not big enough for my eyesight to make out the spot.

My 5mm planetary EP FOV 55 (x240) was good, but just not high enough mag for me.

I do have a 4mm (x300) and that was just about the right size and good contrast, but it's just a basic one with little FOV and was hard to keep in view for long. Might need to look into getting a good 4mm, as well as A decent 10mm for DSO. (Could do with winning the lottery),

Lost contrast at x400 (3mm) but wanted to see how far I could push it.

I guess that on an exceptional night ( I know we don't get many of them) x480 might be amazing. I think my scopes specs says the maximum is x400.

Trying to avoid buying to many eps by having 2x & 3x barlows until I see what works best for me.

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I believe that it transits about every 10 hours, so will try and plan a late evening viewing.

480 was a nice size to view, but you are right about the contrast and turbulence. 240 was nice and sharp, just not big enough for my eyesight to make out the spot.

My 5mm planetary EP FOV 55 (x240) was good, but just not high enough mag for me.

I do have a 4mm (x300) and that was just about the right size and good contrast, but it's just a basic one with little FOV and was hard to keep in view for long. Might need to look into getting a good 4mm, as well as A decent 10mm for DSO. (Could do with winning the lottery),

Lost contrast at x400 (3mm) but wanted to see how far I could push it.

I guess that on an exceptional night ( I know we don't get many of them) x480 might be amazing. I think my scopes specs says the maximum is x400.

Trying to avoid buying to many eps by having 2x & 3x barlows until I see what works best for me.

Well done on seeing the red spot. Like many astro targets, once seen it's somewhat easier the next time around !

I can understand your aspirations for using loads of magnification to get a large image in the eyepiece but over the years I've been observing it, latterly with a 12" scope of excellent optical quality, I've found that you see more contrast and detail on Jupiter by stepping back from very high magnification slightly.

It's not just about the seeing conditions. The nature of Jupiter's surface features are subtle contrast variations rather than hard edged dramatic ones and as such you need to maximise the contrast in the image rather than it's scale.

On really exceptional nights I have used 318x successfully on Jupiter (Pentax XW 5mm eyepiece) but most often it's my 8mm and 6mm Ethos (199x and 265x) that provide the best views of the giant planet.

With your 8" scope the corresponding values are that bit lower.

By all means throw power at it and see what happens but it's also well worth reducing the power when you want to pick out the more subtle surface features.

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My scope is 10"and I understand the logic of using a lower mag ep and the quality is much sharper with a 5mm, but a bit too small to see the spot. I might not be giving myself enough time to acclimatise to a new piece and keep changing them to get a bigger image.

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My scope is 10"and I understand the logic of using a lower mag ep and the quality is much sharper with a 5mm, but a bit too small to see the spot. I might not be giving myself enough time to acclimatise to a new piece and keep changing them to get a bigger image.

The GRS is quite straightforward to see at 120x - 150x with my 4" refractor. It can actually get less obvious when too much power is used I've found.

But keep experimenting and find out what works best for you.

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Nice report!

Apparently the spot is getting darker again after being rather faint in the first decade of this century.

What amazed me is that all the clouds are only about 60km thick, in a layer above an ocean of liquid hydrogen and helium. I always thought the GRS was a whirling storm that plunged thousands of miles into the depths of the gas giant!

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Congratulations!

When I first finally saw the GRS and a transit, I turned into Michael Flatley for a few minutes, wobbled the decking like crazy but it made a whole bunch of previously poor nights utterly worth it!

Edited by ghostdance
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My scope is 10"and I understand the logic of using a lower mag ep and the quality is much sharper with a 5mm, but a bit too small to see the spot. I might not be giving myself enough time to acclimatise to a new piece and keep changing them to get a bigger image.

The GRS is quite straightforward to see at 120x - 150x with my 4" refractor. It can actually get less obvious when too much power is used I've found.

But keep experimenting and find out what works best for you.

Exactly so, John. I have no problem seeing the GRS with my 76mm refractor and an 11mm plossl. For me, the best views are provided with said frac and a Zeiss 10mm ortho - about x125.

Norfolk Star Gazer, the key to observing Jupiter is patience. Many successive viewings will train your eye to see finer details and differences in tone. Having a lower magnification (not too low though!) enhances the contrast between the tones. These days I spend more time looking at fewer objects - last year I had a 4 hour session just on Jupiter alone, and I often go outside just to look at the Moon and nothing else.

Edited by Roy Challen
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I sort of came to the same conclusion on Sunday morning and spent from 4.30 to 7.00 just looking at Jupiter. Most of the time was spend switching EPs, dodging clouds,clearing the dew and going into the garage for a quick warm up.

I did notice that occasionally the skies were so clear that even at 3mm I got a very good view and could make out the bands in great detail, but sadly it didn't last that long and by the time I saw the GRS it was getting light, so lost the contrast.

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My scope is pretty much the same as yours. For me, the best contrast is at x150 (8mm). But, it is too small to really get into the detail. Generally, 200x (6mm) is the max before the gain in size isn't worth the loss in contrast.

But! On the odd night (once a year if you are lucky in the UK) x250 + gives near photographic views. You don't forget those nights!

Well done on the GRS. Sounds like you had to work for it.

Paul

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PS. Don't forget the Moon shadow transits across the face of the planet. They make it seem almost 3D.

Paul

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