Europa occulting Ganymede, 8th May

[AstroJunk (Jonathan)]

Originally Posted by DaveGee

Thanks Jonathan, I'm kind of embarrassed that my pathetic light curve is mentioned on this thread.

Don't listen to him, Dave is one of the finest observers in his field of astronomy (sorry for further embarrasment).

[bird (Anthony Wesley)]

Originally Posted by DaveGee

Hi Anthony, The more samples, the smoother the curve, Can give a reference time? To the nearest second is OK for these events. Can you synchronise your PC clock to a time server. Dimension4 works well.

Regards
Dave

Dave, I have about 21000 frames covering the event, each one has the UT embedded accurate to a small fraction of a second :-)

cheers, Bird

[Dennis]

Hi Anthony

Wow – you have done something quite special here, quite extraordinary. The occultation is one of the most beautiful animations I have ever seen, not only in what it reveals but in the planning and execution behind it all.

This is truly one of those rare, breakthrough moments in amateur planetary imaging to be savoured to the full. Well done Bird, well done indeed.

Cheers

Dennis

[iceman (Mike)]

Brilliant animation, very well captured.

How did you decide on 30s per run? If it was Io would you go even shorter?

There's a few more like this coming up this season - can't wait to see more of them.

[Dennis]

In recognition of Anthony’s outstanding animation of Europa and Ganymede, can I suggest that we present him with the inaugural RAPMO trophy; aka the “2009 Römer Award for Planetary Moon Occultations".

In 1676, Ole Römer, a Danish astronomer working at the Paris Observatory, made the first real measurement of the speed of light. He made a systematic study of Io, one of the moons of Jupiter, which was eclipsed by Jupiter at regular intervals, as Io went around Jupiter in a circular orbit at a steady rate.

Römer found that for several months the Io eclipses lagged more and more behind the expected time, but then they began to pick up again. In September 1676, he correctly predicted that an Io eclipse on November 9 would be 10 minutes behind schedule. He explained that as the Earth and Jupiter moved in their orbits, the distance between them varied. The light from Io took time to reach the earth, and took the longest time when the earth was furthest away. When the Earth was furthest from Jupiter, there was an extra distance for light to travel equal to the diameter of the Earth’s orbit compared with the point of closest approach.

Cheers

Dennis

[Glenn Dawes]

I too would like to offer my congratulations Anthony.
You made Space Weather:

http://spaceweather.com/

It is very rare, especially when you realize the earth only passes through the Jupiter satellite plane ever 6 years.

There are lots of Jovian mutuals coming up this year. They are detailed on p 115 of Astronomy 2009. I think the eclipses would be the most appealing for visual observers. There is one on the morning of May 17 when Callisto eclipses Io.

Regards

Glenn

[StephenM (Stephen)]

That's brilliant Anthony!!! Very well done!

Cheers,
Stephen

[bird (Anthony Wesley)]

Originally Posted by Glenn Dawes

I too would like to offer my congratulations Anthony.
You made Space Weather:

http://spaceweather.com/

It is very rare, especially when you realize the earth only passes through the Jupiter satellite plane ever 6 years.

There are lots of Jovian mutuals coming up this year. They are detailed on p 115 of Astronomy 2009. I think the eclipses would be the most appealing for visual observers. There is one on the morning of May 17 when Callisto eclipses Io.

Regards

Glenn

Yep, that one is on my list :-) It lasts almost 11 minutes too!

Guys, there are many more Jovian occultations and eclipses coming up - in decent seeing anyone with a well collimated and cooled scope can create these animations... we only get a chance once every 6 years, and the next time Jupiter will be low in the north for us, so effectively it will be 12 years until this chance comes around again!

ie you should all have a go at this, it's lots of fun and you can get a result that shows no surface details at all and still feel happy :-) a rarity in the planetary imaging world.

cheers, Bird

[jjjnettie (Jeanette)]

I second that Dennis.

[Liz]

Amazing animation, and congrats for Spaceweather!!!!!

[bird (Anthony Wesley)]

Originally Posted by iceman

Brilliant animation, very well captured.

How did you decide on 30s per run? If it was Io would you go even shorter?

There's a few more like this coming up this season - can't wait to see more of them.

Thanks Mike. The 30s for each frame roughly came out of wanting 1200 raw frames, actually its about 31.5 seconds or something @ 38fps.

I figured that 1200 raw frames should yield at least 250 decent ones to process so that's what I did for each frame of the animation. Some of the later groups of 1200 had more than 250 good frames but I limited them all to 250 so the frames would all look roughly the same with identical processing.

If the seeing was better then I could shorten the groups to 600 frames, still looking for 250 to process and that would be about 15 seconds per frame.

cheers, Bird

[spacezebra (Petra)]

Congrats Anthony on an excellent capture, animation and the top news story on SpaceWeather!

What a great achievement.

Cheers Petra d.

[pelu]

Incredible, Anthony. I have made visual and photometric Phemus a lot of years ago, but this is a higher level...

[tonybarry (Tony)]

This is splendid stuff. Congratulations!

Regards,
Tony Barry

[prova]

Well done Bird, I think we're all waiting to see what you can do with the 16"!

Cheers
Prova

[Terry B]

This is very clever.
Well done.

[g__day (Matthew)]

Very, very well done and thanks for sharing!

[DavidU (Dave)]

Awesome job Bird !
Excellent, can't say enough.

[dcalleja]

This is just remarkable. I've never actually seen this imaged before

[Ric]

Amazing imaging Bird.

What a fantastic prize to capture.

Top stuff indeed.