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[Centaur]

Jupiter’s Galilean satellites #2 Europa and #3 Ganymede are in the midst of a series of four weekly dual shadow transit events. The third will occur during the night of October 30/31. While Europa is actually transiting Jupiter so will its shadow and that of Ganymede. During these events, #1 Io will undergo both an occultation by Jupiter and an eclipse by Jupiter’s shadow. Prior to these events Ganymede will transit Jupiter.

I’ve created three preview graphics for October 30 at 23:45 CDT, one as viewed from above Jupiter’s north pole and a second as viewed from Earth. The third is an event timetable. They can be seen by clicking www.curtrenz.com/astronomical then going to the page for Superior Planets.

Descriptions and photos of these events would be welcome additions to this thread.

[Paulie pchris00]

I'm going to try to get this documented.

[patrickm]

I'll see what I can do as well. If last night was precursor, I'd be better off just going to be early though.

Unfortunately, Jupiter is too low to see from my back deck, so that leaves Horner or Sunken Gardens, which should be fine for planetary even though the street light was replaced. Hmm...

Seeing is supposed to be rotten tonight, but I think that affects larger scopes like Joe's more than the rest of us. :-)

Still haven't caught a transit, so I am intrigued.

[patrickm]

Hillary, I had a great time too. I think you posted your feelings on a different thread, and I did too. Cut and pasted it over here when I realized...

Thought Paulie would have posted his write up by now. He was on fire on Saturday night, and I got to take advantage of his knowledge and his Dob! It was the perfect scope for a chilly, windy, cloudy night. "We" could pack it up quickly to head into the house for a warm up. And skies where so cloudy, that any kind of alignment would have been rough, as I discovered on my own later in the morning.

Paulie caught just about every entrance and exit, and Hillary and I were lucky enough to take advantage of his hard work. I supplied moral support, hot green tea, and a warm retreat. Having Curt's calcs allowed us to pick and choose our time time outside and in.

We also did community service by babysitting a teen who had too much to drink and was abandoned in the park for about an hour by his "friends." Nice goin' kids. Remember, never leave a man behind!

Awaiting Paulie's full report. I learned a lot!

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[Paulie pchris00]

I am also awaiting my full report. I think most of the images are useless, but the notes are good. I slept all day yesterday, worked last night, then had another story to work on after I did a quick lunar and solar daytime viewing around noon. I need to get ready to go out tonight for karaoke, but I will post the full report just as soon as I can.

That's a nice Moon shot, btw. Not the same one you sent me though?

[patrickm]

Don't remember which one I sent. I shot quite a few til the clouds finally won out.

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[patrickm]

Another. With clouds moving in.

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[Centaur]

Nov 1, 2010 15:20:22 GMT -6 patrickm said:

Another. With clouds moving in.

Patrick, are those really shots of the Galilean satellite events I predicted for this thread? Wow, you really have some telescope!

[Paulie pchris00]

That's Ganymede after it crossed Jupiter's disk.

[patrickm]

Ouch. Noted.

Was just trying to distract you while we waited for Paulie's write up.

[Paulie pchris00]

Paulie is accepting donations so that I can afford to call off work tonight, so I can spend my day writing, voting, and maybe some more observing in the evening. My bank account # is xxxx-xxxx-xxxx-xxxx.

Thank you.

[Chicago Astronomer - Astro Joe]

Paulie,

A very generous Nigerian will gladly accept your bank account info.

[Paulie pchris00]

Yes, I get their emails all the time! Lol! i can't believe how much inheritance I have from a continent on which I have no direct, recent ancestry.

[Paulie pchris00]

At long last...



Last Saturday night I was looking forward to observing the many events involving the Galilean Moons, but I was also committed to doing something Halloweeny with Hillary. We even had a public argument on Facebook about what to do that night. Enter Patrick to save the night for us, and mix astronomical observing with a Halloween themed Séance party at the Saki record store. This was something for both of us to enjoy.


sakistore.blogspot.com/2010/10/blog-post.html

sakistore.blogspot.com/2010/11/sakis-seance.html


The night’s events, Galilean and otherwise, were to start around 7 PM, and we arrived right on time. Patrick saw us walking up to the store and came out to greet us. I was tempted to grab my Dob for a quick look-see at the Jovian system, but thought better of it. In hind sight, I should have, since Ganymede was due to start it’s transit at 7:15. We had no observation of Ganymede before it disappeared in front of Jupiter’s disk.
,

Observations were made in front of the store between 7:40 and 7:45, with lonely Callisto far off to the right (inverted image), Europa nearing Jupiter from the right, and Io off to the left. More observations were made between 8:30 and 8:46, to confirm trend of motion. We had something of an audience both times, mostly curious party-goers out for a smoke break. We shared the Jovian system with pleasure, explaining how each of the inner three Moons would be interacting with the planet that night.






Hillary in front of the store. It was a fun spot to observe, with costumed people coming by to have a look at Jupiter & Moons.



Although the forecasts were favorable for a clear night of observing, during the second round of viewing clouds were starting to move in from the Lake. Not cool, but they were scattered, and could be dealt with.


Since we had missed Ganymede’s point of contact to start it’s transit, our first observed event was the start of Europa’s transit, scheduled to occur at 9:22. Clouds were increasing, and seeing conditions had deteriorated, and I thought I observed first contact at 9:17. The total transit was to begin at 9:26, and this fits with what was observed, although between clouds, Europa could still be discerned near the limb until at least 9:33. The show had already ended, and Patrick had left to go home and feed his pets a few minutes before. When the clouds became impenetrable, I concluded observations in front of the store, and Hillary and I met Patrick at his house.


When we arrived, we had a few minutes to kill before the next event, Ganymede reappearing on the left limb (again, all of these descriptions are based on an inverted view). Patrick treated us to green tea before heading down the street to Sunken Gardens Park, my Dobsonian in tow. Ganymede was set to emerge at 10:15, with last point of contact at 10:25. Seeing conditions were still bad, but the clouds were not as bad as when we left the store. Therefore, Ganymede was not seen emerging from the limb until 10:21. Once we had all seen Ganymede slipping away from it’s master, it was already time to get ready for the next event, Io disappearing behind Jupiter. For a few minutes, though, we had the two moons together, just to the left of Jupiter.


The partial occultation of Io, starting at 10:33, was observed as best as could be done. At 10:36, Io was still partially visible, and should have been for at least another minute, but a cloud moved in and stole the moment of total occultation. With half an hour before the next event, we bounced around the sky. Orion was showing above the trees, and the Great Nebula was observed and discussed, particularly the 3D depiction of it in the Hubble IMAX film.


By 11:00, it was time to turn attention back to the Jovian system. Ganymede and Europa’s shadows were to fall upon the great disk in short succession, Ganymede starting at 11:04, and Europa at 11:14. Due to foreshortening on the limb and poor condition (saying nothing of my scope’s imperfect collimation), Ganymede’s shadow was not observed until 11:18, with separation from the limb noticed at 11:21. Europa’s shadow was more subtle, and I do not have it noted when it was first observed. Cloud cover thickened at 11:26, so we returned to Patrick’s house to warm up and refill mugs of tea. Although we returned for one last round at midnight for Europa’s emersion from the Jovian disk at 12:06, I do not have Europa noted as visible until 12:11, just as it’s partial transit was ending. The late night chill and worsening clouds cut our session short after that.


Hillary and I hung out for a little while before calling it a night, and heading back to Indiana. As Patrick’s Moon images above show, conditions did improve after we left, but I think we made the right call. We had seen a number of Galilean events already, more than I normally see in a good week. Patrick and Hillary are free to comment, but I will readily admit that after the first observation in front of the store, I was very focused and determined to stay on schedule, and observe every subsequent event after that. It was one of my most disciplined observation sessions ever, despite setting up and breaking down (Patrick is maybe slightly jealous of this capability) five times during the course of the night, at two locations. I like my leisurely tours of the sky when I’m alone, but this was an action packed night out in the Jovian system, and I wanted to document it as best possible. Unfortunately, my images are not worthy of posting, and don’t prove much of anything, except that I have a lot of ground to make up in the realm of astrophotography. Thank you to Patrick for hosting Hillary and me. I had a fun time, both at the Saki Séance party, and the observing during and after. And thanks to both of you for putting up with my single-mindedness of what’s next, what’s next, what’s next???

[patrickm]

Belated pictures of actual astronomers observing the actual transits. No moon included. ;P



Paulie and Hillary. Paulie a little ghostie because of movement between HDR frames. Oooooooohhhh

Paulie doing serious work

Paulie loafing

Hillary keeping an eye on drunken teen on park bench. Ghostie Paulie who can't sit still unless at the eyepiece.

[Paulie pchris00]

Of course I look ghostly. It was Halloween weekend!

Btw, I was looking through some of the images of Jupiter and Moons from that night, and some of them might be good enough to post. I might try to edit them into my narrative above later. If so, I will post an announcement here.