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Jupiter and Ganymede, Jan 6th...

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#1 Eddgie

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Posted 07 January 2013 - 04:11 PM

Another night of very good seeing. Not perfect but first ring was forming and breaking up on a red star a degree away.. What is that star anyway? Very red.

Seeing was though, quite good. I would get some flaring on the smaller moons, though it rarely showed on Ganymede.

Speaking of Ganymede, with great patience, I was able to spot the little white spot of Osiris. It was just inside the limb on the Jupiter side. Not easy to see, but when I went in to do a simulation, it was where I had observed it to be. I also felt like I was perhaps seeing a hint of surface detail, but it would come and go.

Jupiter was somewhat disappointing. GRS was past the limb, but so oblique, I could not see it for most of the session (about 90 minutes). The BA oval though was quite prominent and showed a surprising orangish color when it was near the meridian. Lots of contrast varience in the major belts, but not really a lot resolved. Also, while images are showing many fairly large ovals that are in a line just south of Oval BA, but once again, these have escaped me. I have not really had a good view of these lately.

Some festoons, but faint.

Also, I was a bit disappointed. The sky was clear and seeing seemed fairly good, but when I put in my 13mm eyepeices, I simply could not get a bright image.

I have not really had much opportunity to do high power observing with the binoviewers, but the dimming appeared to be strong enough that I thougth the view was much better using a pair of 15mm Plossls. Seeing wasn't perfect though, so maybe 263x was about as high as I could go and still see a lot of detail.

Dew AGAIN! Maybe something is wrong with my dew strip. Power was once again maxed. There was still a lot of space before Jupiter would have drifted behind a tree that overhangs my back yard, so this was another frustration.

Sadly Jupiter was not as good as I had hoped given the seeing, but again, dew kept me from seeing GRS come well into view and even images are showing that the area to the east of the GRS complex is not that feature rich other than Oval BA and associated ovals.

#2 azure1961p

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Posted 07 January 2013 - 06:18 PM

The sky's clear as a bell right now in CT so Im hoping to possibly get good seeing tonight tho cleardarkskys sais I should get lousy seeing (again). It's been wrong in the past so I can hope.

To date I've not seen Osiris as a dot or singular spot but rather a polar brightening. That was without any fans running. I'm hoping the active cooling now pays off on that feature. I'm confident it will.

The red star is actually a fairly challenging double tho last time I looked I didn't have this information and never bothered to pay it close enough attention. Well that and the seeing stunk. Ill try tonight seeing willing.

On a seperate note:

Jupiter right now is prime time viewing. Have supper, set up and observe and be in bed on time. The way it seems to work out tho and with all the planets is that everyone gets these early observations in st hours of the morning I can't entertain on my schedule so by the time it finally reaches a prime time viewing slot most everyone's donevwithnit and ready for the next planet to swing by so essentially I'm observing prime time alone! Or well, with you Ed lol alone.

Pete

#3 Rick Woods

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Posted 07 January 2013 - 08:18 PM

Ed, you were using your C14?

I've never come close to seeing detail on Ganymede. But, I think my eyes may be part of the problem.

Pete, you've seen Osiris in your 8" Newt? I should try it in mine!

#4 Eddgie

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Posted 07 January 2013 - 08:49 PM

Yes, C14 with Mark V binoviewer and 15mm Vixen NPL Plossls. I was having trouble because the view seems rather dim at 300x using the binoviewers. I have seen it more easily at 350x in the past using monovision in the C14. But I could see it at 260x with the 15mm Plossls.

It shows as a slightly brighter spot just inside the limb in the C14 when it is well placed. This is always where I seem to be able to see it best... When it is just inside of the limb.

Seeing has to be pretty good to spot it, so I am at a loss as to why I was not seeing more details on Jupiter. I am afraid it might be the dimming associated with binoviewers. In my last two sessions of very good seeing, as I pump up the magnification, I am noticing that the image just isn't as bright as I remeber from nono-vision.

Anyway, C14 with Mark Vs and 15mm Plossls for about 265x. Was fleeting when seeing, but at moments would show.

After the sighting, I went in and fired up my Astronomy program to check position against my sighting, and the simulation showed it where I had earlier observed it.

#5 Asbytec

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Posted 07 January 2013 - 09:13 PM

The bright red star is BU 87, unequal pair at 1.6" arc, if I recall. It's a very nice colored double. It needs some magnification.

Yea, Pete, after dinner observing is too early for me. In bed by when? :)

#6 azure1961p

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Posted 07 January 2013 - 10:33 PM

Ed, you were using your C14?

I've never come close to seeing detail on Ganymede. But, I think my eyes may be part of the problem.

Pete, you've seen Osiris in your 8" Newt? I should try it in mine!


Yes but it's an 8/10 or better seeing thing. The light of that moon needs to all settle down onto itself for one good no BS view. When I have seen it though it wasn't separated from its nearby pole. Instead Osiris looked more like an extended polar cap. It's a lack of resolution that shows it larger and more sprawling than it really is. But really rewarding.

After reading Eds account tonight I tried for a time but the seeing never obliged to give even one flare less shot at it. Plus where it was tonight I don't think was a good angle. When its 10" or so off the preceding limb (if I recall right) is when that hemisphere shows best.

At anyrate it was good to read Eds account of it all above with the 14.

Pete

#7 Eddgie

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Posted 08 January 2013 - 10:10 AM

Yes, I think the Io thread was useful in explaining why things look they way the do. At 14", Osiris is more spot like, but it is not at all resolved to a shape. More like a faint, slightly unfocused star just inside of the limb, which is the only position I really have ever seen it well.

This could just be coincidence though, that seeing was good and that it was well placed.

But I have clearly seen the outline of Galilee Regio on Ganymede though, but only when it was well placed, and only once. It showed as a "C" on the limb, but with a very flattened top. I have looked for it since, but once again, this feature has to be exactly placed for it so show I think.

I use an astro-program to model it. Usually I do this after observing to confirm my observations, but again, I am finding that these details seem to have to be well placed to really postively see them. At least that is my theory.






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