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Festoons or barges, who saw what on Jupiter last night?


scarp15

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Saturday 15th and I distinctly saw two dark areas on the NEB, which I initially deduced as being barges, yet I was using my 76mm refractor and barges are small features and I felt not entirely convinced that the aperture that I was using would pull them out. Could they be a facet of festoons, as I believe that there is some prominence in two large dark areas currently in this vicinity and for which may have some association with the GRS in the SEB?

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Interesting thanks, I was observing until approx 11.20 and the GRS was coming round on the disc. I am accustomed to observing barge features with my 8" scope and I am still gaining familiarity in what is observably achievable with my 3" scope (which is a surprising amount so far) and using up to 120X. Is a bit of a conundrum and may well have involved both simultaneously barge and festoon activity. 

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I can see quite a lot of details on Jupiter with my 60mm, but many of these are not clearly identifiable. 

After many observations, I am quite sure I can see: North equatorial belt (NEB), north temperate belt (NTB), north polar region (NPR), south equatorial belt (SEB), south polar region (SPR), GRS.

When the seeing is very good and the contrast allows, I can see half hollow above the GRS and large festoons. I often wonder whether the festoons I see are actually pairs of festoons.

Faint turbulence on the equatorial belts are also visible when the air is steady.

As far as the magnification, I use 75x-150x on Jupiter, but the best results are from 100x-150x (this because the size of Jupiter becomes large enough to pull out features more easily). 

 

I've never managed to clearly identify barges or white ovals. They are possibly there, but so far I am not able to distinguish them. Are they feasible with a 76mm? No idea. It might be that the aperture is just enough for spotting these features under perfect seeing. 

 

That planet is a treasure of details. :smile:

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I think that there appears to be a bit of interesting activity in the NEB right now. This is my first meagre attempt at Jupter this season in terrible seeing, over my neighbour's roof last night early evening. There appear to be quite a few dark patches in the Belt, and the paler band above it (The North Tropical Zone, I believe it's called) looks an interesting shade of orangey-pink. Worth closer examination when it's a bit higher and in better seeing.

33913882512_a8c6e14e0a.jpg

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I saw two festoons and a dark elongated area of the NEB last night when viewing with my Tak FC 100. I wasn't sure if the elongated area was a barge or just a darker section of the belt. There were a number of pale eddies in the SEB as well. This was just as the GRS came onto the disk and shortly before the thin misty clouds turned into thicker obscuring clouds :rolleyes2:

After the clouds came there might have been several barges and a small tug boat on the planet for all I could see of it !

 

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The 90mm SV shows festoons, barges and white ovals, the 10" really starts to open them up and the 15"...well its at another level again. The 90mm likes 150x to just over 200x on Jupiter and the warmth of some Televues is appreciated. The little 3-6mm NZ seems made for these smaller refractors.

Iain, your 76mm will support more mag in those good conditions which might help even further, great observing btw!

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8 hours ago, Piero said:

I can see quite a lot of details on Jupiter with my 60mm, but many of these are not clearly identifiable. 

After many observations, I am quite sure I can see: North equatorial belt (NEB), north temperate belt (NTB), north polar region (NPR), south equatorial belt (SEB), south polar region (SPR), GRS.

When the seeing is very good and the contrast allows, I can see half hollow above the GRS and large festoons. I often wonder whether the festoons I see are actually pairs of festoons.

Faint turbulence on the equatorial belts are also visible when the air is steady.

As far as the magnification, I use 75x-150x on Jupiter, but the best results are from 100x-150x (this because the size of Jupiter becomes large enough to pull out features more easily). 

 

I've never managed to clearly identify barges or white ovals. They are possibly there, but so far I am not able to distinguish them. Are they feasible with a 76mm? No idea. It might be that the aperture is just enough for spotting these features under perfect seeing. 

 

That planet is a treasure of details. :smile:

Festoons, garlands, barges, the GRS and shadow transits can all be seen under reasonably good conditions through a 76 mm. Often white ovals can be on the small side but even they would be visible if large enough. Binoviewing, rather than the mono view, makes these targets so much easier to detect when using small apertures. Only a couple of weeks ago, a friend had brought his 76 mm Apo round for a night's observing, and the small scope even in mono mode delivered an exquisite view of Jupiter that,  although small, was bursting with intricate detail. Sadly I didn't make a sketch but I've attached a pic of the scope.

Mike

 

2017-04-03 08.14.52.jpg

2017-04-03 08.07.20.jpg

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On 16/04/2017 at 22:13, mikeDnight said:

Festoons, garlands, barges, the GRS and shadow transits can all be seen under reasonably good conditions through a 76 mm. Often white ovals can be on the small side but even they would be visible if large enough. Binoviewing, rather than the mono view, makes these targets so much easier to detect when using small apertures. Only a couple of weeks ago, a friend had brought his 76 mm Apo round for a night's observing, and the small scope even in mono mode delivered an exquisite view of Jupiter that,  although small, was bursting with intricate detail. Sadly I didn't make a sketch but I've attached a pic of the scope.

Mike

 

2017-04-03 08.14.52.jpg

2017-04-03 08.07.20.jpg

can't see it mike :hiding:

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3 hours ago, faulksy said:

can't see it mike :hiding:

Oh, youve just been spoiled by all that aperture, light grasp and resolution Mike! Or it could be over exposure to all that UV from distant starlight in your 20" has damaged your retina. ?

Mike

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2 hours ago, mikeDnight said:

Oh, youve just been spoiled by all that aperture, light grasp and resolution Mike! Or it could be over exposure to all that UV from distant starlight in your 20" has damaged your retina. ?

Mike

:happy11:

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7 minutes ago, triton1 said:

I'd think looking at that picture anyone would find it hard to distinguish between a festoon and an oval.

Maybe this is a little clearer ?:

 

jupiterSketch1.png

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7 hours ago, triton1 said:

I'd think looking at that picture anyone would find it hard to distinguish between a festoon and an oval.

Hi John,

Sometimes the area in the armpit of the festoon can appear noticeably brighter and can appear to be a white oval. This can especially be the case where the festoon reattaches itself to the equatorial belt, creating a garland.

Mike 

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On 16/04/2017 at 11:48, Moonshane said:

Based on your scope and assuming midnight Calsky suggests festoons? Images for 3" & 16"

 

 

tmp40878010996410.jpg

tmp61056981970348.jpg

Thanks for posting this comparison. It is making me think quite a lot. 

I have to say that I do see more details than those shown in the first image although my telescope is a 2.4". For instance I can see the white lane on the SEB, which in the second picture is right above the GRS, but I cannot identify that is a kind of chain of white ovals. When the seeing is superior, half hollow between the GRS and the SEB is also visible to my eye. The North temperate belt is thinner. Then again, there are irregularities on the two equatorial belts and the two polar regions, but I struggle identify how these really are, so the contour, the faint colours, and the extension of each feature.

I find that observing in the twilight largely increases colour contrast. Active cones? 

Thanks again for the images.

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Great Jupiter viewing again last night with the red spot going across late evening. The pictures above are very helpful to identify the various different features. I saw two clear extensive festoons in the EZ. The white lane in the SEB was also very clear. Red spot really popped out - more than I've seen in previous years. I used binoviewers at 150x which gave the most sharp and easy to see detail. No issues either with dew due to the eyepiece heater straps. Not far away at all from the 16" image posted by moonshane above!

Also tried my new 4mm delite for the first time. This gave 245x which was a bit too much for Jupiter but still had a pleasing view. Nice and comfortable eyepiece. Finally I had a bit of fun powermating my ES 92 12 to give around 160x - surprising easy to use given the height of the total contraption!

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Of the features discussed, I've found those white ovals some of the hardest to spot with small scopes. My 12" dob shows them and the more promenant ones are glimpsed at smaller apertures but they are not easy prey by any means. Festoons can be subtle and, oddly, they seem to "pop out" a bit more with a little averted vision. Not a technique that is generally needed with Jupiter but it's worth trying when you are teasing the subtle stuff out.

Nice report Gavin :icon_biggrin:

 

 

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