Jupiter (Ganymede & Io in transit), Mars, Saturn in good seeing, 11th March

[andyc]

Some nice results from a session at the weekend. Good seeing for the double transit of Ganymede & Io, and although I was a bit disappointed with my G & B channels, the R was very crisp. And satisfyingly sharp Mars with clouds on Elysium Mons, and my first Saturn of the season has the polar vortex & hexagon in IR.

Jupiter gallery (https://photos.app.goo.gl/hUV8ABBreO6hBMjw1)
Mars gallery (https://photos.app.goo.gl/SaWBDUvmRnnudhCr2)
Saturn gallery (https://photos.app.goo.gl/fmgVczrwN6Y23hEj1)

[Tinderboxsky]

Very, very good Andy. Ideal seeing makes such a difference. Looking forward to the three Oppositions.

[h0ughy]

Talk about triple treat, fantastic results

[Camelopardalis]

Nice set there Andy, well done :thumbsup:

[Wavytone]

Ah very nice, indeed !

I watched the transit of Ganymede's shadow for a while but hit the sack by the time you took those.

You're really tempting me to hook up a camera to my scope as it seems I have a fair chance of good seeing at the local park...

[blinky]

Great images! Nice definition on the moons and with the rings of saturn. How high was saturn when you imaged it?

[andyc]

Thanks everyone!

Leigh, Saturn was about 57deg up, imaging close to 6am in Sydney. High enough I'm not considering the ADC for it.

[blinky]

ADC? I thought you don't need one when doing RGB because your only getting light from one color at a time?.

[Troy]

Good images and the moons look great.

[andyc]

Because the spectral bands of your R, G & B filters are not narrow, dispersion still operates on the ~100nm band of each mono filter. As dispersion affects blue more than red, if the blue channel is particularly bad and the planet is < ~60deg high, it may well be worth it. This article (http://skyinspector.co.uk/atm-dispersion-corrector--adc) gives a lot of good info and data, with an example of the effect on mono imaging of Jupiter. For blue, the effect is 1" at 40deg, quite a bit larger than the resolution of either of our scopes. Another good chart is here (https://www.cloudynights.com/topic/509819-adc-demonstration-with-saturn/page-2#entry6759978) and some miscellaneous discussion here (https://www.cloudynights.com/topic/533371-adc-and-mono-imaging/). My take-away from it is that I'll probably not bother very much, especially this season when the planets are very high, but it's worth keeping in mind to try.

[bigjoe]

Thanks for sharing these Andy ..have seen clouds visually over Elysium in a 7" mak.at 600X, and sighted an albedo feature as an apparition, where Olympus Mons should be...last Mars opposition..

Cheers bigjoe.