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[Centaur]

During the night of October 11-12, there will be simultaneous transits across the apparent disk of Jupiter by the shadows of three of its Galilean satellites. This has not occurred since 2004. For those who are wondering, having four simultaneous shadows is impossible. The shadows of Io, Europa and Callisto will all be in transit from 23:30 CDT to 00:46 CDT (UT-5).

I’ve created preview graphics of the triple shadow event as seen from above Jupiter’s north pole and as seen from Earth. They can be viewed at: www.CurtRenz.com/jupiter

Now that Jupiter is beginning to reenter our evening sky, I’ve resumed publication of my nightly event timetable and graphical array of Jupiter’s four Galilean satellites and their shadows. They can be accessed at the same webpage.

Photos and descriptions of the triple shadow transit would be welcome additions to this thread.

[Paulie pchris00]

Impossible because of the orbital resonance of Io, Europa, and Ganymede?

[Centaur]

Oct 1, 2013 18:54:48 GMT -6 Paulie pchris00 said:

Impossible because of the orbital resonance of Io, Europa, and Ganymede?

Yes, Paulie, due to that resonance a close grouping of all three of those can never be viewed from Jupiter. It's one of the few true solar system resonances and is not merely an approximation. Callisto is not part of the resonance, so its shadow always participates in a triple shadow event.

[Centaur]

Part of the reason that triple shadow transits are rather rare is that Callisto must always be involved. It goes through alternating periods of about three years each in which it either can or cannot cast a shadow on Jupiter. We recently entered on of those periods in which Callisto shadow transits are possible. In the cases of the three inner Galilean satellites, they always cast their shadows on Jupiter when they pass between Jupiter and the Sun during each synodic revolution around Jupiter.

[Centaur]

Here are my predictions for the transits including partial phases in Central Daylight Time during the night of 2013 OCT 11-12.

22:24:57 - 00:45:59 CDT - #4 Callisto's Shadow
22:28:02 - 01:02:36 CDT - #2 Europa's Shadow
23:29:37 - 01:45:41 CDT - #1 Io's Shadow

00:46:02 - 03:04:31 CDT - #1 Io
01:00:10 - 03:45:43 CDT - #2 Europa
10:04:30 - 13:31:25 CDT - #4 Callisto

[Centaur]

My timetable for tonight's triple shadow transit across Jupiter and the later transits of the Galilean satellites is now available on my Jupiter webpage: www.CurtRenz.com/jupiter . It includes start and finish times for both the partial and total phases of the events. Timing verifications from observers would be appreciated.

[Chicago Astronomer - Astro Joe]

I'll be observing this tonight and hopefully capturing it.

Thanks Curt!

[Centaur]

Oct 11, 2013 10:48:58 GMT -6 Chicago Astronomer - Astro Joe said:

I'll be observing this tonight and hopefully capturing it.

Thanks Curt!

You’re welcome, Joe. Good luck with pix.

Jupiter will rise tonight at 23:22 for the Adler and 23:23 here in Arlington Heights. The times will not be much different throughout Chicagoland. It will rise near the east-northeast, and more precisely at azimuth 59° which is 31° to the left of due east.

[Paulie pchris00]

Curt, I've got your graphs printed, sky is clear, and everything is set up and ready. Now I just have to wait for Jupiter to get above the horizon.

[jglover]

Oct 11, 2013 10:48:58 GMT -6 Chicago Astronomer - Astro Joe said:

I'll be observing this tonight and hopefully capturing it.

Thanks Curt!

I'll see what I can see but unfortunately Jupiter has yet to clear my house and I've got about a 10% cloud cover rolling through as well......

[Chicago Astronomer - Astro Joe]

Conditions were very poor for this event at the Private Chicago Astronomer Observation site. With Jupiter being so low, it was mostly a bubbly blob most of the time.

Three of us, (Bill, Javier and myself), looked for the three shadows, but we only saw one really, but this single pics out of many showed two...

More laters, but this was a practically a non-event for Chicago area astronomers.

[Centaur]

At least you gave it a try, Joe. Thanks for sharing what you did get. Folks further west would have been completely shut out.

Here’s a photo of the event emailed to me by my Belgian astronomical author friend Jean Meeus. It was taken by his friend Bart Declercq in Belgium this morning at 05:03 UT.

[Paulie pchris00]

I have no data. From the time Jupiter appeared over the trees at 11:29 PM CDST until the total shadow transit of Callisto, the Jovian disk showed no detail. Seeing conditions were terrible. I gave up after that.

[Centaur]

Oct 12, 2013 20:03:28 GMT -6 Paulie pchris00 said:

I have no data. From the time Jupiter appeared over the trees at 11:29 PM CDST until the total shadow transit of Callisto, the Jovian disk showed no detail. Seeing conditions were terrible. I gave up after that.

Sorry, Paulie; next time I'll try to improve the seeing conditions.

The next triple shadow transit will occur on 2014 JUN 03, although it will be a daytime event for Chicagolanders. Then the event on 2015 JAN 23-24 will be in the middle of the night for us. After that, no more triple shadow transits until 2032. All this according to Jean Meeus in his book "Mathematical Astronomy Morsels".

Today Jean Meeus sent me the photo set seen below that was shot by his fellow Belgian Leo Aerts on October 12 at 04:32, 04:36, 4:40, 04:48 & 05:28 UT.

[Paulie pchris00]

Very nice.

I knew it was a gamble with Jupiter so low in the sky, but the seeing was maybe the worst I've ever seen. Even when Luna was riding fairly high earlier in the night, it was shimmering badly. Maybe I'll see the triple shadow transit in 2015. I'm sure I'll finally see Callisto's shadow before then.

[Centaur]

For those who were disappointed with the seeing conditions for the triple shadow transit, I offer a consolation. During the early morning of November 19 their will be a dual shadow transit while Jupiter is high in the sky. I already have the preview graphics posted on my Jupiter webpage: www.CurtRenz.com/jupiter

My nightly timetable for events involving the Galilean satellites and their shadows is posted on that webpage around noon each day. Preview graphics for upcoming dual shadow transits can also be found there.

[Paulie pchris00]

I like the nightly timetables. As Jupiter starts rising earlier, I should be using them quite a bit.