These planets are difficult to image. They are large but a very long way away.
Below is a monochrome picture of Uranus with four of its satellites. Move your mouse over the picture to see which is which; the numbers in brackets are the magnitudes. Both Uranus itself and the small star on the right are grossly over-exposed and so appear much bigger than they really were. The bright halo around Uranus is also an artifact of the over-exposure and the processing. Miranda is also in the picture but it was only 2 arc-seconds away from Ariel and, at magnitude 16.5, I am doubtful if I would have detected it even if it hadn't been so close to the much brighter Ariel. For comparison, Ariel was 10 arc-seconds from Uranus.
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Date and Time: 6th October 2010 22:34 UT Set-up: DMK 21AF04 with Astronomik CLS filter on the LX200 Capture: ICCapture, 85 frames, 4", gain 877 Processing: Registax, 66 frames stacked, gamma 1.7, wavelets 1 = 10, 2 = 5, histogram 20-130. PhotoImpact, contrast 10, Focus Magic 6,100, contrast 40. Distance 2,862,000,000 Km (19.13 AU) Size 3 arc-sec |
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Date and Time: 6th August 2004 22:23 UT Set-up: ToUcam 840K at prime focus of the LX200 Capture: K3CCDTools, 146 frames, high gamma, 2", 41% gain, meter 218 Processing: K3CCDTools, X2, 98 frames stacked, unsharp mask 5,0,100. Distance 4,355,800,000 Km (29.1166 AU) Size 2 arc-sec |
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I think 15 seconds is too long an exposure for my LX200 at this focal length (5,000 mm). Neptune is not this shape. Move your mouse over the image to see an attempted to correct this with a program called Focus Magic which calculates what the original image must have been given a certain amount of movement. I don't know how reliable the result might be. Date and Time: 29th August 2006 22:13 UT Set-up: ToUcam 840K with X2 lens on the LX200 Capture: K3CCDTools, 47 frames, high gamma, 15", 45% gain Processing: Registax, 16 frames stacked, wavelets 1 = 10, Histogram 60-225. Distance 4,361,300,000 Km (29.153 AU) Size 2 arc-sec |
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On 5th October 2017, Neptune's satellite, Triton, occulted a 12.7 V-magnitude star. I managed to capture this event by taking a series of pictures of Neptune across the time of the expected occultation. My results for the time of the occultation and its length agree very well with the predicted values. Click on the image to see a detailed discussion of this event. Date and Time: 5th October 2017 23:49 UT Set-up: MX716 camera at prime focus of the LX200 Capture: Star_mx7 30 second exposures Processing: Enhanced by a non-linear stretch in the Star_mx7 software. Distance 4,359,400,000 Km (29.141 AU) Size of Neptune 2 arc-sec |
