Hmmm, I'm a little puzzled....!

[Kokatha man]

This mono image (and the billious green achro-generated one too from my 6" achro) shows a distinct little "spot" or shadow in the EZs (Southern component of the Equatorial Zone) meaning the light-coloured band directly above the plane of the ring system.....with South up and East to the left-hand side of the disk of Saturn as per the conventions taken from the A.L.P.O. Saturn Section and "The Saturn Handbook."

Image taken at 8.56 pm Central Australian Standard Time on 22nd April which my (very) fuzzy calculations has as 11.26 am GMT/UT....? Not sure which day though....!

I've inverted my image to give it a Northern Hemisphere appraisal though I'm assured South should be "up" by convention - this now places my little "spot" on the hemisphere below the rings in that first light band below them - and 2 or 3mm in from the RHS...!?

Does this have any correlation with MrEd's Rhea transit image.....which to me seems to be in Saturn's other hemisphere.....so maybe it's a "spot" but it didn't seem to be as it was visible in early stages of Registax processing too.....and has anyone a link to the Saturn Moon (and shadow) transit times and dates this year - I've googled for an hour and a half through all sorts of dross and not found anything yet!!!

SatR4Proc#2B&WRotateavi059.tif

[MrEd]

Hmmmm

It does not appear to be an artifact.

Also in my experiance spots on Saturn are

genrally brighter in nature and usually appear

yellow,white or green.

It looks like a shadow transit its about the right size and shade.

My advice would be to run a planetarium

programme like starry night and rewind time

so to speak to the day and location.

They will show any transits occuring.

Failing that some of the glossys print transit times

or you can go to your national (or international)

astronomy association saturn section and drop them a line.

Over here i use the BAA and a chap called Mike Faulkes or

Paul Abel are good guys to help out.

HTH

Ed Sampson

[Kokatha man]

Thanks for that Ed.....I didn't think it was an artefact, for a number of reasons - although the fellas on my local forum here are giving me stick saying I'm seeing things etc etc....!:)

In fact it only came to light because I processed this avi.....the whole thing was an exercise in trying to quantify "seeing" over a number of different nights, from visual markers through to eyeballing through an ep at power and taking images: all using Saturn as the yardstick.....

Good advice on the resourcing too.....I'll follow it up!

[jgs001]

According to this assuming the time calculations are correct it could well be Enceladus, but I can't tell from the teeny tiny image it provides whether it's supposed to be in front of or behind the planet.

[Paul G. Abel]

There is currently a white spot in EZs, if you give me a estimate of the date and time you took the picture, I can work out the CM and check for you if you wish.

-Paul.

[Kokatha man]

There is currently a white spot in EZs, if you give me a estimate of the date and time you took the picture, I can work out the CM and check for you if you wish.

-Paul.

Hi Paul - Time and date as above.....8.56 pm Central Australian Standard Time which figures at 11.26 am GMT/UT here in South Australia.....taken on the evening of Wednesday 22nd April 2009 here (yesty evening - not sure which way the dates run from here to you....!)

Any assistance greatly appreciated!:)

[Cloudwatcher]

If that is a moon shadow and if I were a betting man I'd put my money on Enceladus............. each way of course!

Have a look at this overlay from starry night pro......... a hole has been cut to show your image underneath........

[Paul G. Abel]

Any assistance greatly appreciated!:)

I think I have the answer for you. If you observation is on 22nd April 2009 at 1126UT then I calculate a longtude of system 1 to be CM1= 164 degrees.

Using WINJUPOS at this date and time it is clear that no satellites are transiting.

However, I've checked the drift chart for the white spot which currently resides in the EZs and it is at about longitude 160, so I think it is entirely possible that you have imaged the genuine white spot in the EZs.

Hope this helps!

-Paul.

[Kokatha man]

Thanks fellas.....this is gunna take some digesting....!:):D