Saturn near opposition showing Seeliger effect

[Tulloch]

A terrible night for imaging (19 July) - rain a few hours before, high winds, 95% cloud cover, why did I bother? Well, I've never seen the Seeliger effect before, so I set up at 10:30, arranged some ice packs on the back of the OTA and hoped that the rain would stay away for an hour or two.

I finally got a 2.5 minute break in the clouds (of which about half of that was useful), blasted away with the camera and hoped for the best. The image below shows a soft, but bright rendition of the planet near opposition, compared to one I took a few weeks ago in better seeing conditions with exactly the same capture settings and processing applied. The first time I made this image I didn't believe the result, so I did it again, making sure that processing applied between images was identical.

Andrew

Image details: Celestron Evolution 9.25" SCT @ f21.0 with 2.5x TV PM, ASI 224MC, 7500 frames stacked in AS!3, sharpened in Registax, final touches in Photoshop Elements, shown at 150% captured size.

[RichardJ]

Hi Andrew,

Great capture and demonstration of this effect:thumbsup::thumbsup:

Hugo von Seeliger would be very delighted.

RichardJ :)

[AstralTraveller]

Great capture and great perseverance. And I've learned something! Thanks.

[Camelopardalis]

That’s pretty astonishing really :thumbsup:

[Nikolas]

sorry to ask "seeliger effect"?

[glend]

Opposition Surge. It simply refers to a brightening of the rings that occurs during Earth and Sarturn Opposition when less of the ring particles are in effectively in shadow.

[Tulloch]

Here's one reference to the effect, a quick Google search will give you more.
https://astronomy.com/magazine/stephen-omeara/2014/03/saturns-opposition-effect

It's basically that when the Earth and Saturn are aligned with the sun, the particles making up the rings scatter coherently, making the rings appear brighter.

Hope this helps, Andrew

[RichardJ]

Hi Andrew,

Very interesting article. I was inspired by your post do my own comparison and animated GIF between a shot I took in early June to one on July 23. It is similar to yours.

Richard.

[Tulloch]

:)

[Retrograde]

That's a very cool comparison, Andrew.
Nice images too. :thumbsup: