Uranus and Neptune 15.9.19

[John Hothersall]

SPX350 F17.5, ASI290, Baader 610nm filter. 0.1"/pixel.

The night showed some good seeing but variable which as it progressed became less variable.

With Uranus I used 12min captures at 75fps and 0.1"/Pixel gain 590, the moons are very faint but the brightest Titania was seen with the last 4 captures which were the best showing bright north area detail on the 3.67" disc - derotation of 4 sets. Uranus only reaches 49.5 degrees. I took some rgb but it was too green so I changed it to a more pleasing cyan colour. The moons are clearly visible showing the good seeing, next time I may try 0.15"/pixel to see if I can get Miranda which was too faint. I included some raw frames to show you seeing was not too bad. This is the first time I have got any detail on Uranus because I did not have the 610nm filter which works really well.

Neptune gave me 6 good 10 min sets but the derotation showed no white cloud detail. Over 2hrs 10min I got some Triton motion after Dennis suggested motion could be seen. I used 25fps full gain 0.1"/pixel. I also got some colour. Autostakkert had problems stacking this small planet so I used Registax, don't know what I did wrong.

Regards, John.

[Dennis]

Really nice work John and quite an interesting series of images from Raw data to finished and polished product.

Very impressive image scale (separation between Uranus and brighter moons) and I reckon you should be able to comfortably dig out the more elusive Miranda with your set up, when she gets to her max of around 9.5 arc secs.

Cheers

Dennis

EDIT:
Added SkyTools 4 Imaging screen capture for 15th Sept 2019.

[BlueGumby (Graham)]

Wow! Really impressive John. Thanks for sharing.

I only just managed to actually find Neptune myself on Tuesday night and see its tiny disk (confirmed location using star chart). It's a giant leap from that to be able to take worthwhile photos which you have done.

cheers ... Graham.P

[Merlin66 (Ken)]

John,
Do you think the cooled ATiK 314 would have given any better results?

[John Hothersall]

Thanks guys.

Hello Ken, the venerable 314 is a great ccd from the past and the ASI290 is the new back illuminated cmos technology which is so much more sensitive there is no comparison and noise free so cooling makes no difference with fast exposures. 290 has 1e read noise vs 314 3-7e read noise. 290 has such fantastic frame rates we use USB3 and SSD's to cope - I just love the 290!

Regards, John.

[Merlin66 (Ken)]

I agree the recent CMOS camera work pretty well.
I use the ASI 174 and 1600 for solar imaging. I can get up to 400 fps and definitely need the SSD drive.
For spectroscopy however the jury is still out on CMOS. The ATiK 314 is still widely used.