Finding Saturn's moons

[old_eyes]

I was looking at Saturn last night with my C6-SCT, and I could easily see Titan, and could also see a faint dot the other side of the planet which was probably Rhea and Dione combined (Stellarium says they we very close together); however I could not see Tethys between Rhea and Dione and Saturn. It is about the magnitude as the other two. Was their combined light enough to make them visible? I was using a 25mm plossl with 2x barlow for a magnification of about 120. Going higher with my eyepieces did help as their was quite a lot of high thin cloud around.

Interested in what I could expect to see.

old_eyes

[Iris]

Tethis was close to Enceladus last night - making another combined point - I managed to see both (pairs - i couldnt split the four moons) with my C8 @ about 100x (I was using a focal reducer) - ramping up the power to 200 failed to resolve the two pairs.

Maybe there wasnt just enough light for the 6" to grasp - they were pretty faint to me.

[Doc]

The more aperture the more you will see. I have no problem in seeing all 8 moons with 16".

But even so I'm sure a 6" scope should have a limiting magnitude of at least 13 so in principle you should see at least 4 moons.

[Macavity]

I could see Titan, and "a.n.other" (forget which!) the other night - With my new MAK150. Another moon was supposedly in transit. A tad disappointing, but it was nominally a "first light" and I blamed the recent "custard skies" for good measure!

[David Galvin]

There is a nice grouping of four of the moons this evening, hopefully you will have clear skies. Bad seeing may make it difficult but give it a go.

The diagrams below are from WinJupos and should give you an idea what to expect at 21:00 U.T (22:00 BST).

Note that Mimas is 'behind' Saturn untill 22:37 UT (23:37 BST).

Regards from Dave Galvin.

[Macavity]

Thanks. I must admit I forget to look so far away and off axis. My recent view of Titan (poised just above one side of the rings!) was interesting - Certainly (or optimistically) the orange colour seemed quite striking... in the MAK?

[brianb]

Here's an image I captured last night (Apr 14) - can anyone identify the faint moon just to the left of the rings? The other four I identified using my copy of Starry Night Pro; to the left, Tethys above Titan; to the right, Enceladus then Dione; Rhea touching/almost embedded in the glare from the rings to the lower right of the globe.

2010 Apr 14, 2224 UT. Celestron CPC1100, prime focus, "L" filter from Astronomik type 2c colour seperation filter set (i.e. just UV & IR blocking), Imaging Source DMK21 camera. 100 x 1 sec exposures stacked, selected from 200 frame AVI. North up; east (following) to the left.

Iapetus was also very easily seen, but is out of frame to the lower left on this image.

Edit: Never mind guys, the "unidentified" moon is Mimas (10 mins work with BAA Handbook). Wonder why SNP doesn't know?

[Doc]

Thats Mimas Brian.

Sorry Brian didn't see your edit.

[David Galvin]

Yep, you have got it exactly right.

Earlier there was a shadow transit of Rhea but, unfortunately, I was unable to detect it. This computer simulation is created by the software WinJupos and is very good once you work out how to use it.

[Jove]

Sky & Telescope have a little online Moon-position tool too, here, which is quite handy. You can even get it to account for the upside-down/mirrored image in your scope.

[SirFoo]

Sky & Telescope have a little online Moon-position tool too, here, which is quite handy. You can even get it to account for the upside-down/mirrored image in your scope.

Thanks Jove. I downloaded WinJUPOS but it seemed quite tricky to use. The sky and telescope tool is much easier. I think I saw titan on Wednesday night. It was off to the left of Saturn as I was viewing it through my scope. Needed to use averted vision to really see it.

[old_eyes]

Did a little better tonight.

Saw Titan, Rhea and Dione on one side of Saturn, Tethys/Enceledus as a single dot on the other side. Iapetus further out. I checked where Hyperion was in Stellarium, but no sign of it. probably could not expect to see it with a 150mm SCT, esp. with all that moonlight around.

Picking 'em off one by one. A lovely and intriguing sight.

old_eyes

[Stu]

I was having a quick look on 12th, admittedly with a mount which wasn't tracking (a challenge to say the least!) I found I could see two pairs too but couldn't split them into four using my mak (8"). Checking Stellarium it was Rhea, Dione, Tethys and Enceladus. Trying higher magnification didn't seem to help. I'll let you know what I see when the mount is set up correctly next time