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Io eclipse tonight, 11/8

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#1 Ira

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Posted 08 November 2012 - 10:20 PM

I watched the eclipse of Io tonight around 23:30 UT. It was the first eclipse of a moon by Jupiter I have ever seen! I know they are not rare, but you do have to be out at just the right time, and I never have been before.

Io slowly dimmed as it passed into Jupiter's shadow. It took perhaps 60 seconds to go from full magnitude to just fading out. This led me to two questions:

1) What is the smallest telescope required to see the phases of the eclipse on Io? I was using a C8 under perfect transparency and seeing and could not see anything except the slow dimming of the moon.

2) There must be bright stars that are occasionally occulted by the shadow, not the disk, of Jupiter. When was the last time that happened and when will be the next? Does anyone calculate an ephemeris for such events on a regular basis?

/Ira

#2 Centaur

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Posted 09 November 2012 - 12:10 AM

2) There must be bright stars that are occasionally occulted by the shadow, not the disk, of Jupiter.


Ira, stars shine due to light they emit through nuclear fusion. They do not reflect sunlight in the manner of the Galilean satellites. Therefore, stars can be occulted by the disk of Jupiter, but they cannot be eclipsed by Jupiter's shadow.

#3 Ira

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Posted 10 November 2012 - 12:11 PM

Duh. :foreheadslap:

#4 Ira

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Posted 10 November 2012 - 12:12 PM

Ok, so anyone know what size scope is required to see the phases of the eclipse ?

/Ira






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