Jupiter and Moons

My first pictures were of Jupiter and Saturn, because they were bright, easy to find and quick to image (my first, uncovered, images of them were about .02 seconds in length). Many of these pictures did not turn out very well: though that's what often happens with planetary imaging, which is very susceptible to atmospheric seeing and the will of the gods.

This first one is what Jupiter looks like the first time you image it in CCDOPS, before adjusting the contrast. Those three dots to the upper right of it are three of its moons (The four brightest moons are Ganymede, Io, Europa and Callsto). These three are Callisto (topmost and dimmest), Io (left most and middle brightness) and Ganymede (right most and brightest). Europa was behind Jupiter when I took this picture (it would have been visible if I had taken the picture about 3 hours later or about two hours earlier).

Jupiter, .2 sec: Taken 9.10.2000 at Goodsell Observatory through an LX200 at f/10

Here is what you see after adjusting the back and range to bring out detail of Jupiter (the back sets pixel value for black, and the back+range sets the pixel value for white and other pixel values are scaled linearly from there). Notice that the moons are gone, but we can see some of the bands in the atmosphere!

Jupiter, .2 sec: Taken 9.10.2000 at Goodsell Observatory through an LX200 at f/10
Here is what it looks like after being resampled (the camera's pixels are rectangular -- 23 by 27 micrometers -- and so pictures are actually stretched horizontally, until they are resampled):

Jupiter, .2 sec: Taken 9.10.2000 at Goodsell Observatory through an LX200 at f/10
And finally, here is a combined image taken with RGB filters (red, green and blue: each filters out light that is not that color, so when you combine them in Photoshop or The Gimp on each of the Red, Green and Blue channels, you get a color image), with exposure times of .2, .4 and .6 seconds -- I covered the telescope with a light reducing cover thingy, which meant I could take longer images without washing out the camera, and so get better detail.

Jupiter, combined RGB: Taken 9.10.2000 at Goodsell Observatory through an LX200 at f/10

This image involved resampling the pixels, combining the three filtered images, moving them so that they would overlap and finally doubling the size of it, to make detail more visible. I discovered late in the term that taking very short exposures very close together is the best way to get good planetary images. The RGB images for this were taken a few minutes apart, so it is not as clear as it might be. I have not had time yet to try to improve on these.

Return to John's Astronomy page
Return to Goodsell Special project page
Return to Goodsell main page
John Parejko
Last modified: Mon Feb 5 23:25:17 CST 2001