Saturn Image 2025/05/03(UT)
Clyde Foster,Andy Casely
C.Foster,A.Casely
| Clyde Foster |
Below average conditions yesterday morning. Despite that,some severe processing (additional sharpening,increased contrast and brightness,all in Registax) still brought out the rings. Possible that the increasing negative tilt of the rings is counteracting the reducing solar declination? The bright spot at upper right in the enhanced view is not shown as a moon in Winjupos,so is either an artefact or possibly a star.[Clyde Foster : Khomas,Namibia]
| Andy Casely |
In nearly perfect seeing conditions (for me). it was three days before Saturn's equinox (late on the 6th UT I think, though sunrise on the rings takes ~4days). The silhouetted rings are to the north of Saturn's equator due to the 2.1° ring tilt, no shadow of course so close to equinox. The RGB is nice and clean, with excellent definition of the silhouetted dark rings against the planet, plus five moons. It's one of my favourite planetary shots now, with the moons and no rings! It wasn't feasible to easily make a smooth view with the rings stretched, as the rings were incredibly faint. There are five moons: (from lower left): Dione, Rhea, Mimas, Tethys (just emerged) and Enceladus. The first IR image was deliberately overexposed and further stretched to bring out the faint rings. Beautiful and ghostly, and the rings are currently much darker than the ordinarily very faint moon Mimas, just above Rhea on the left side. Kudos to the ZWO ASI585MM too, the nice low even noise profile is a big improvement on my old 200M. A question: I have a persistent faint dot just to the right of the rings in the first IR, which could only plausibly be Janus or Epimetheus if it is not noise. JPL Horizons ephemerides indicates (I think) that Epimetheus is not far from that location, but Janus is behind Saturn (guessed from coordinates). Is there a way to check this better (an accurate plot for position, etc)? 16th mag seems awfully faint, but this overexposed set, excellent seeing that has an Airy ring around 13.5mag Mimas, plus no ring glare, so it might be possible to get fainter moons without the rings' glare. I'm guessing it's noise, but it's quite a coincidental place for what was by far the brightest other bit of noise in the frame... There is also another IR and a short colour image with the ASI462MC.
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