Saturn Ring Spokes...Probable Artifact

Hello all,
I use an Atik color camera (1C) for my planetary images and the Atik B&W for Lunar. But, I have gotten the impression that many feel the B&W with RGB is superior. Recently, in addition to the color camera, I use my B&W to image Saturn. Imagine my astonishment when the B&W image, after processing, showed Spokes in saturn's Rings! Going back and reviewing the individual frames I believe now that dirt on the camera likely caused the false spokes. I have had more trouble keeping the Atik camera clean than my Toucam by far, even with an IR filter screwed on. It is as if there is dirt inside the camera that shakes loose. No matter how much time I spend cleaning the lens it is not long before dirt shows up on the image when taking the AVI. And, even though the image moves, it appears the dirt can be picked up as in this case. Thoughts?

Jim Phillips

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Hi Jim -

While in Cedar Key we observed a radial darkening very similar to your image. Ours was the night of Feb. 10. One of my friends described them as spokes - I didn't feel the seeing was good enough to detect such a challenging feature. But it definitely was more prominent and further extending than the minima where the B ring meets the crepe ring.

very interesting!
Alan

Hi Jim,

I'm not qualified to comment on the "Spokes", but it is a superb image.

Ed Roach

Jim -

On shmutz on the CCD, my Astrovid camera use to have a terrible time with flecks that came off the metal 1.25" nosepiece everytime I unscrewed it, or screwed in a filter. A small can of compressed air is helpful, though sometimes a gentle swipe with isopropyl alchohol was needed. Wasn't as much of a problem with the planets which I could usually adjust position on the chip, but a bear for the moon and sun illuminating the whole chip.

Alan

After boosting the contrast on the "spokes", they appear radially arranged to me, which seems unlikely if the cause was dirt. I've included what I got after toying with the contrast and inverting the light/dark scale.

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Hi all,

Interesting. I 100% agree with Jim's original conclusion of dust problems. Lets me explain why:

We have two high res images of Saturn in visible light (the ATK image is basically a BW verison of the colour one in terms of recorded wavelengths) and the colour image shows nothing remotely resembling such features. Also look carfeully at the BW image - the darkening extends across ring A also. This would be highly unlikely in reality that a spoke feature would cross from B to A ring (since they are composed of different materials.) Jim himself admits the dust problems with the camera, and its likely caused buy the Planet steadily drifting in declination during the AVI run in relation to the dust mark.

With further regard to spokes, in 6 years as the Assisant Director for the BAA Saturn section, i have never recieved an image amatuer or professional that shows definate spoke features in the ring system. The only time ive ever seen them was in the Voyager movies and once in Pic du Midi images in 1997. It seriosuly makes me question the validity of many visual sightings, when *objective* high resolution imagery (in cases in the past during the same times as reported sightings) shows nothing of the kind.

A Saturnian mystery that remains i guess

Best Wishes

Damian

Thanks for the comments. I'm still not sure and so will lean toward artifact but...
Anyway, I'm glad I went ahead and posted the image for comments. I had been concerned that if I did I would be laughed at. Thanks for being so nice.

jim Phllips

Hi guys,

I attach a cutout processed to actually enhance the large scale detail we are looking at here. The dark line clearly extends on to the A ring with an odd bright patch ahead of it.

I think what would be of great help would be if Jim could provide some guide as to how long the colour and BW images are separated in time. Otherwise, even if the feature was actually real it can never be confirmed and we could debate until blue in the face

Damian

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