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Six (Oh Well) Saturnian Moons Via 8" Reflector

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#1 E_Look

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Posted 17 June 2013 - 02:16 AM

Evening of 6/16/13, from around 10 or 10:30 PM to 12:30 AM 6/17, it was partly cloudy. There were a couple of intervals in these two hours that I had to just sit and wait for a large cloud mass to pass (I saw that the cloud had an end followed by some clear sky). However, there were still wisps and hazy patches that blew through.

Even so, I was able to get, again, a just a tad less than fair view of Saturn: again, the Cassini division and the planetary shadow on the rings, the north equatorial band (is that what it's called?) was visible, with a smooth progressively darkening (toward the pole) north polar region, and the same beautiful golden color.

But tonight, it was the moons, and their arrangement that occupied most of my time and effort tonight. I had first checked my Sky Safari app and it indicated that Enceladus should be far enough from the rings that it may be more easily seen, along with Iapetus lingering within what may be considered a normal field of view.

And when I finally got my scope out, and without any thermal equilibration of the OTA and its 8" mirror, I could immediately see Titan (of course), with Iapetus farther away from it, but Dione, Tethys, and Rhea forming a slanted line barrier between Saturn and Titan. It was breathtakingly beautiful, like some kind of jeweled tiara on top of the head, which is the ringed planet itself.

But what really got me was that I could from time to time see, by an averted gaze, Enceladus, though mainly at 250x, and yes, Saturn was sort of stable enough so that its features could be seen at this power. I was also able to glimpse Enceladus once or twice only at 200x. And now, something which some may find very disputable, but I think I saw it, again by averted seeing, four times, actually, and I'm talking about Phoebe! It was a faint ghost of a dot that popped in and out, at about the right position where Phoebe should be by the planetary disk. It wouldn't have been Hyperion, which would have been farther out from Saturn. In fact, it appeared at the same times that Enceladus did, indicating that the seeing and transparency settled and cleared enough at those instants for these faint moons to be viewable; Enceladus appearing at about 11 o'clock and Phoebe at about 5 o'clock around Saturn. I don't know why I couldn't then see Hyperion, though truth to tell, I wasn't really looking for it. I was able to catch these two fainter moons three times at 250x and once at 200x. At lower powers, down to 63x, only the four usual moons and Iapetus were visible.

I have seen Enceladus before, but never with Iapetus present in the field of view, and this is the first time I've glimpsed Phoebe! And it's the first time I've seen seven moons of Saturn in one field of view!

I will say that I am fairly surprised, again given what the naked eye perceptions of the sky conditions were, but I believe this was greatly aided by motorized equatorial tracking. And, I don't care what any nay-sayers will neigh about; I think I've been observing long enough, despite still only having the knowledge of a rank newb, that I can tell when I really saw something via averted vision. The object, even if requiring averted viewing, will pop in, and make an almost physical impression, a sort of soft pricking on the eye as its image appears, as was my experience in the past with Enceladus and Triton and the E and F stars of the Trapezium. Transient eye noise doesn't have that kind of a feel. Viva short f/l TMB Planetaries! And, good night!

#2 azure1961p

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Posted 17 June 2013 - 07:21 AM

TYC5558-0359 1 is an 11th magnitude field star that was tucked tight within Saturns Moons orbital complex. Do you suppose Ed that this extra point of light may have affected how you identified the moons ?

Magnitude 17 is an incredible capture - no nays - but the moment I saw the field star deep on Darirns midst a red flag came up. What do you think?


Peyr

#3 Asbytec

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Posted 17 June 2013 - 07:31 AM

Ed, wonderful catch. Enceladus is a tough cookie. One night when I first got my scope and was out observing Saturn, it struck me all the tiny dots surrounding the planet. I realized they were moons and quickly sketched their positions. Turns out, one of the faint ones I managed that night seemed to be Enceladus.

Turns out, repeating the observation was more difficult. I cheated so knowing the position of Enceladus before hand, and boy it took a couple of nights of calm skies, moderate power (about 160x with a 12mm HO ortho) to actually glimpse Enceladus again with enough certainty to make the call.

I think transparency, very calm skies, and throughput are important, as well as Enceladus being as far from Saturn's glare as possible. Well, for a 6" to do it, anyway. Congratulations on your observation, that's a touch one.

Phoebe? I dunno, maybe Pete has a point. How far is Phoebe from Saturn? It's gotta be orders of magnitude more difficult than Enceladus and Mimas. I've not heard of anyone observing it, so I don't know anything about it, really. No doubt something was there, your description of the observation sounds accurate to me.

#4 gfeulner

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Posted 17 June 2013 - 09:02 AM

Ed. See my post about the occultation last night of an 11th mag star. Maybe that's what you saw. Gerry

#5 E_Look

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Posted 17 June 2013 - 10:39 AM

Okay. Maybe I should have check my PC astro software instead of just a phone app.

Where was this star relative to Saturn last night?

#6 David Knisely

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Posted 17 June 2013 - 12:56 PM

I may have just a few doubts about seeing Phoebe in an 8 inch. At its brightest, it is about magnitude 16.4, which is tough for me to hit even in my 14 inch under dark sky conditions. Hyperion (mag. 14.2) can also be a little tough, although I have seen it in my 10 inch Newtonian and it would be possible in an 8 inch as well. It is possible you just saw a faint background star instead. Clear skies to you.

#7 E_Look

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Posted 17 June 2013 - 01:13 PM

David, Norme, gfeulner, and Pete,

I stand corrected. I checked it's magnitude: it's 17. There is no way to see that through a 8" mirror on a night of variable seeing and transparency.

Now, what DID I see? The I was unable to locate in Voyager (III) any star in that specific vicinity that could make me think it was a moon. I can't locate either the star gfeulner mentioned in my software, so I wouldn't know where around Saturn it would emerge from occultation. If it is 11th magnitude as he says, it would be visible to me on clear nights and by averted viewing on less clear nights.

Oh, well, the ol' foot in mouth trick, I guess, and I missed by THAT much, measured on astronomical levels. Let me edit the title of this post...

... oops, I see I cannot. If some mod might be inclined to save me from my hubris and change it for me, that'd be nice. :foreheadslap:

#8 gfeulner

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Posted 17 June 2013 - 02:18 PM

Ed- According to Azure1961P's post the star was TYC 5558-0359. My Stellarium program didn't give the number but just that it was Mag 11. With north up it proceeded from right to left actually going behind the rings in the southern part at the 5 o'clock position and going behind the planet roughly around 8 o'clock and appearing again around 10:30( EDT). Unfortunately I couldn't observe it here in New Jersey because of my neighbors trees. If I can backtrack my Stellarium program, I'll see if I can give you more definite times. Gerry

#9 gfeulner

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Posted 17 June 2013 - 02:28 PM

Okay, I ran the Stellarium program back and the star went behind the planet at approximately 8:40 and reappeared at approximately 11:15 EDT. It actually was behind the rings for a while before going behind Saturn but here in the East it was still too bright at 8 o'clock or so to see it. Unfortunately I think what you saw was this 11th mag star. Gerry

#10 E_Look

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Posted 17 June 2013 - 02:33 PM

LOL. I suppose you are right. Whereabouts on Saturn's circumference did it emerge? It may very well be what blinked in and out of view; Enceladus did, so I am also supposing that such borderline viewable objects to a 8" reflector will show only in those instances when the seeing temporarily calms, coinciding with one of those few but extant patches of clarity last night.

Boy, how I felt after I came inside though!

#11 E_Look

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Posted 17 June 2013 - 02:34 PM

To the mod (RLTYS?), thanks!

#12 gfeulner

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Posted 17 June 2013 - 04:08 PM

It reappeared at the 7 o'clock position. Even if it wasn't a moon and was the star that's still a good catch because you didn't know before hand it was there and it was so faint. Gerry

#13 E_Look

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Posted 17 June 2013 - 05:22 PM

Thanks, but what I saw, with my rotated inverted view, with North on top canted to the left and the other directions accordingly, at 5 o'clock. So I wonder what I saw, if actually anything!

#14 azure1961p

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Posted 17 June 2013 - 09:56 PM

Hi Ed,

The first pic is the wide angle view. West is to the right, north is up (kinda)...

Pete

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#15 azure1961p

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Posted 17 June 2013 - 09:57 PM

And here's a super wide view including Phoebe...

Pete

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#16 azure1961p

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Posted 17 June 2013 - 09:58 PM

And here's a close up of the interloping star...

Pete

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#17 azure1961p

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Posted 17 June 2013 - 10:05 PM

Well that's the star/Saturn from central western Connecticut anyway.

I read your posts and I appreciate your thoughts here because I know you are a careful observer . I figured the added point of light here may have misdirected identification. Hey it happens!!!

If youd've seen Phoebe - wow - and in Saturns glare glow - yikes!!!!


Pete

#18 gfeulner

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Posted 17 June 2013 - 10:31 PM

Very good illustration Pete. If you don't mind my asking, what program did you use? Gerry

#19 azure1961p

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Posted 17 June 2013 - 10:58 PM

Ahhhh - SKY SAFARI (Plus) via my iPhone V. I have the expensive $40 pro version on my iPod but its not needed for my 8" reflector as Ill never glimpse EVER the faint stars and such it maps out so beautifully. If I had a 12" or bigger reflector Id have the pro on my iPhone too. Such as it is tho...

It is a beautiful app outdone in this respect only by the sheer vastness of its information on myriad objects . It contains a staggering amount of great in depth information on even the most obscure things.

A lot of folks seem to love it.

Pete

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#20 E_Look

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Posted 18 June 2013 - 12:39 AM

Thanks, Pete. That's how it looked in my Sky Safari display, too. This is what I'm wondering about- neither in Sky Safari nor in Voyager was there anything visible south of Saturn before you get to Hyperion. It could very well be just eye noise, but it was repeatable- three times at least. I will confess the glare of Saturn made Enceladus, which is brighter by far than Phoebe, hard to see; I could only see it fleetingly by averted vision.

Eye noise... most likely! Suspiciously, it appeared generally when Enceladus appeared, and disappeared with it.

#21 sdr92114

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Posted 23 June 2013 - 12:26 AM

i have a vintage orange tube 8" sct and im trying to webcam and registax5 the cassini division. i cant find it with a barlow. too dark. any tricks. tried using eyepiece projection with my t3i rebel but image too small and again with a barlow image too dark, cant find saturn, any advice?

#22 azure1961p

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Posted 23 June 2013 - 02:56 PM

Get a flip mirror alignment attachment for your webcam attachment. Next - forget about dslr if u have a webcam. It'll never compete with a decent cam . It seems cluster intuitive but the vids of a very small cam and the post processing can create near miraculous results.

Pete






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