Some recent Jupiter and Saturn images....

[geoflewis]

After a 2 year hiatus, in the last few weeks I've finally been able to reacquaint myself with our two gas giants Jupiter and Saturn. They've been really low down, particularly during 2020 when my time was consumed with Mars, but they are now slowly gaining a bit of altitude, which will continue to improve for us northerners over the coming years.

 

28-29 August 2021

My first outing was on the night of 28-29 August, starting with Saturn which transits first, followed by Jupiter. Jupiter had Io & shadow in transit so I spent most of my time there. The images of Jupiter are displayed south up as I understood that is the preferred orientation of the BAA, but after a discussion with Dr John Rogers, the BAA Jupiter section director, north up is now preferred, so my future images will be north up.

 

 

 

9 Sept 2021

My 2nd outing was on 9 September. Seeing was less good for Saturn. Jupiter now displayed north up with Oval BA nicely seen.

 

 

 

15 Sept 2021

The night of 15th September offered the best seeing this apparition, but I was clouded out early on so did not try for Saturn as I wanted to capture Jupiter's GRS which was transitting. Whilst my capture sequence included IR as well as RGB filters, the detail in the RGB was excellent, not requiring any sharpening by using the IR as luminance, hence the below sequence of four images are just RGB. It will be noted that the seeing started to deteriorate quite rapidly during the 4th capture sequence and by the 5th sequence which I stated, but abandoned, it got really poor. I had hoped to complete the GRS transit, but that was not possible. The best of the seeing was during set 3, so I've also included that image on it's own without annotation for information.

 

 

 

The equipment used is as noted at the top left corner of the annotated images. My capture routine is one or more sequences of videos, alternating through RGB & IR(742nm) filters. Each image typically comprises 3 runs for each filter, e.g. RGBIR-RGBIR-RGBIR. For Saturn I capture 5000 frames per filter for each run. For Jupiter I capture 60s (1 min) per run, so as to minimise any smearing of detail due to Jupiter's fast rotation. I then use Autostakkert to grade and stack best 2000 for Saturn, or best 1000 for Jupiter from each video. The resulting images are shapened with wavelets in Registax6. The IR data, if used, is applied as a luminance (% opacity varies per image, but typically 30%-50%) when building the LRGB image in WinJupos, which is also used to derotate the individual images created from each video. Further sharpening, or other processing is done in Registax6 and Photoshop.

 

I hope that you enjoy the images and thanks for looking.

 

Edited September 17, 2021 by geoflewis
typo

[TerryMcK]

Great work Geof

[geoflewis]

2 minutes ago, TerryMcK said:

Great work Geof

Thanks Terry

[Padraic M]

Well done Geof, amazing captures, and thanks for the information on process. If you don't mind me asking, what are the data in the lower frame System: and CM: ??

[geoflewis]

15 minutes ago, Padraic M said:

Well done Geof, amazing captures, and thanks for the information on process. If you don't mind me asking, what are the data in the lower frame System: and CM: ??

 

Thanks Padraig. Good question about System and CM, which I find difficult to explain, so this is a crib from Wikipedia....

 

Because Jupiter is not a solid body, its upper atmosphere undergoes differential rotation. The rotation of Jupiter's polar atmosphere is about 5 minutes longer than that of the equatorial atmosphere; three systems are used as frames of reference, particularly when graphing the motion of atmospheric features. System I applies to latitudes from 10° N to 10° S; its period is the planet's shortest, at 9h 50m 30.0s. System II applies at all latitudes north and south of these; its period is 9h 55m 40.6s. System III was defined by radio astronomers and corresponds to the rotation of the planet's magnetosphere; its period is Jupiter's official rotation. Wiki

 

CM references the position of each system (I II & III) at the Central Meridian. Monitoring these shows how each system moves relative to each other over time.

 

Hope that helps 😉

[Padraic M]

Wow, thanks Geof, the things I don't even know are there to be known! Google just also gave me an interesting paper from the Juno mission team discussing the 6 (!!!) different coordinate systems that they use for navigation around Jupiter. Why can't it all just be 'left a bit, right a bit'?

I suppose it doesn't help that it's mostly a big ball of gas.

[Carastro]

Great images Geof as i already said elsewhere.

 

Carole 

[geoflewis]

1 hour ago, Carastro said:

Great images Geof as i already said elsewhere.

 

Carole 

Thanks Carole

[Bob-c]

Very nice Geof, well done👍

 

Bob.

[geoflewis]

6 minutes ago, Bob-c said:

Very nice Geof, well done👍

 

Bob.

Thanks Bob

[MarkAR]

This is excellent work Geoff, amazing colour in Saturn and the detail in Jupiter is stunning.