Sunday, 13 January 2013

Fifth moon of Jupiter

I finally found my fifth moon of Jupiter! It's called Himalia, and lives about a degree away from Jupiter in the sky. We recently opened our observatory to the public for three nights, and had clear skies for the last two. After the last people left the dome and were chatting downstairs I set to work obtaining more images of the star field near Jupiter. Unfortunately my Canon 1000D had had a slight mechanical problem, resulting in a brush hair being trapped in front of the sensor. The shutter open-close mechanism suddenly failed to move faster than 1/200" and I tried to clean it with a substandard optical brush. The calibration is a little out. The flat field needs to be updated and also the dark frames I used were from a warmer night. Depsite this, stacking 8 x 30" pictures gave me this interesting image, showing rays of light radiating from Jupiter...and a teency, tiny little dot that was not on the Palomar Observatory Sky Survey red plates. This is Himalia, an outer rock orbiting Jupiter way beyond the four big, bright Galilean satellites that were viewed by many folk earlier in the evening. Some of the visitors got a preview of Himalia on the back of my camera after I had tried to get a few early shots of it. The event was a great success, thanks to the weather holding out and our facilities having been well maintained.

2 comments:

Unknown said...

It's good to see that you're still imaging faint and deep.

Regards
David A

Dr Dan said...

I noticed Himalia has a slight trail, due to the time involved in imaging it. It has moved along with Jupiter among the background stars.

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