Jupiters Moons

[Saturnine]

Hi All

Hope this is the correct area to post this info. For those of us that like planetary observing and imaging there are a few interesting events in the next few days.
On the evening of the 4th , into the morning of the 5th, so this Thursday, there will be a double shadow transit, beginning just after Jupiter rises, from an east coast perspective, would be better from NZ.
Times are for EST, taken from Astronomy 2020, Quasar Publishing.

20:34 Ganymede Shadow Ingress
21:20 Europa Shadow Ingress
23:05 Europa Transit Ingress
23:50 Ganymede Shadow Egress
00:06 Europa Shadow Egress
00:09 Ganymede Transit Ingress
01:52 Europa Transit Egress
03:30 Ganymede Transit Egress

Add in the Red Spot on the CM at 00:38am on the 5th.
Should be quite an interesting show for several hours, guaranteed to be cloudy and or crap seeing for sure.
The BOM weather forecast for this area is actually favourable and CFN, although showing low cloud off the coast also shows the jetstream as fairly quiet. So it may be a good nights entertainment after all.

[Tulloch]

Yep, I've had this on my list since I first noticed the weather in Melbourne was forecast to be clear (and still looks good).

It will be nice to image the planets before going to bed instead of setting the alarm for stupid-o'clock and waking everyone up :) If I get anything decent, I'll post it here.

Andrew

[Max Vondel]

I am planning on viewing if the weather holds.
Thanks for the heads up

[Saturnine]

Just for added interest, on the 6th June starting at 04:30 am there will be a not so common shadow transit of Callisto. One shadow transit may seem like any other to some people but it is a way of seeing the dynamics of orbital motion at play.
There will be a few more Callisto transits this planet season to whet the appetite too.

[Quopaz]

Thanks for that, just converting it to SA times I'm getting double shadow visible from 8:50pm to 11:20pm. Rise at 8:11pm. Weather forecast at this stage- 6pm mostly cloudy, 60% cloud cover.

[Quopaz]

Well that was amazing- I hope you guys got that! I missed the first half hour due to clouds, then they cleared! And the seeing was very good, for a while, then it deteriorated a bit. I started with the 2x barlow doing drift runs, had good views of the 2 shadows. I went till my hands froze then had to go and warm up. When I came back the red spot was coming into view as well, and I swapped to the 3x barlow. So there were 2 shadows and the red spot all at the same time. I'll get something but it will take me a long time to go through it all. Really wish I had tracking. My best views of Jupiter yet. Thanks Jeff!

[Saturnine]

Hi All
Well for once , when there was something not so frequent happening, we actually had clear calm conditions. Maybe too calm as the dew was dripping off everything and the seeing was not very good despite forecasts, typical of around here because of the topography.
Did manage to get a good look at the transits and to take some video but of course had tracking issues with the EQ6, I think that the 10' f6 newt is a bit more than the mount can cope with.
Watching the shadows glide across the disc and the moons disappear against the bright limb along with the Red Spot coming around the limb and traversing the disc as well was worth the effort and am looking forward to a few more in the coming months.
Certainly hope that everyone who made the effort enjoyed the show.

[Tulloch]

Well, in Melbourne we had high clouds cover the sky last night, making high quality imaging impossible. I managed to grab some frames and turned them into an animation (see the Solar System Images forum), but it was a bit disappointing really.

Andrew

[Quopaz]

I was hoping you'd get it and do one of them. Still pretty good and better than what I'll get. Bad luck about the high clouds, I think that's probably why my seeing got worse towards the end. Trouble I've got is with the drift method I can't get enough frames before it rotates. And if I take a 2 min video without drift, just keeping it in frame by hand, I get too much vibration. Have got a goto upgrade kit ordered that I hope will help, but haven't got it yet.

[glend]

For those interested in the moons of Jupiter, there is a thread over on the Cloudy Nights forum, sort of an informal competition to see how many of them you can actually log. One post by IIS member Allan Wade, has him in the hunt to bag a seventh moon in the next couple of months with his 32" Black Widow Dob.

So how many have you actually observed, in total, ever?

https://www.cloudynights.com/topic/710951-five-jovian-satelites/

Of course imaging them should be far easier.

[Tropo-Bob]

Thanks, I saw this about 5.30 and 6.20am. It was noticable how more slowly Callisto shadow moved compared with other shadow transists.

From memory, last year the shadow was missing Jupiter, so I expected the shadow to be very close to the poles. It kind of was, but nevertheless at a lower latitude than I was expecting.

I used my Vixen ED 81with 5mm Delite and 8 & 10mm Radians. This is a great grab and go scope to use when one is still half alseep.

[Saturnine]

I'm glad everyone is enjoying the shadow play on Jupiter, there are a few more Callisto shadow transits in the next few months so there is an opportunity to have another look. There are a few more double shadow transits as well this season.
I have several Gb of video of Callisto' shadow from this morning to process over the weekend, had better seeing this morning compared to yesterday so hopefully some better images as a reault.

[Saturnine]

For all those that are interested , there are double transits by Europa and Ganymede on the 12th and 19th and a Callisto shadow transit starting on the evening of the 22nd of this month. The Red Spot will also be transiting the disc while the double shadow transits are in progress.

[andyc]

Seeing was really bad for the shadow transits on the 4th (a few swear words may have been uttered, these opportunities are not too common with clear skies!), but improved a bit for an image after Io joined the party and Ganymede & Europa were transiting. It's a fun set of multiple transit/shadow events just now

[Saturnine]

Great image Andy, shouldn't expect anything less given your pedigree, pity the seeing wasn't better that morning. Picking up albedo features on the moons is a nice bonus though.
Clouded out down here for last Fridays transits but maybe we'll get lucky for the next installment on Friday morning the 19th Ganymede and Europa' shadows will briefly on the disc at the same time, for 40 mins, from 04: 33 to 05:13. The Red Spot will still be visible near the limb as well.
The weather forecast for that morning is not very comforting though.

[Allan]

I’ve had a good run of conditions this week to continue chasing the fainter moons of Jupiter. Last years opposition I managed to observe Himalia, Elara and Pasiphae.

I’ve been trying and failing for Amalthea for the last couple of years. It’s a very close orbiting moon that perhaps only 20 people have ever seen. Well I finally saw it on Monday for a 15 minute window while it was at max elongation from Jupiter. Took 619x and 808x to see it in the 32”.

I followed that with Carme and Sinope over successive nights. They are around magnitude 18. Still have Lysithea and Ananke on the list, but they are currently closer to 19th magnitude, and will brighten 0.5 magnitude over the next four weeks, so I’ll try for those right on opposition. So far I can’t find any information indicating anyone has ever visually seen these fainter four moons.

So currently I’m at 10 Jovian moons and should get to 12, and I’m up to 27 solar system moons in all. It’s a good challenge if you’re looking for one.

[Tropo-Bob]

In the days before Jupiter’s Opposition (14th July), shadows of its Moons appear on the disc before they transit. Around 7.30 tonight (28th June), Io’s shadow will be upon Jupiter’s disc, whereas Io does not begin to transit till around 7.40pm.

This order reverses after Opposition, so it is worth having a look at these events before and after opposition to gain a 3D sense of the alignments.

[Tropo-Bob]

Calistro's shadow is currently on Jupiter (Thur, 9th July). It will engress at 8.34pm. Calistro will emerge from its transit at 9.48pm.

[Saturnine]

Thanks Troppo, was aware of the Callisto transit tonight and was hoping to catch it, visually and/or imaging but down here we are covered by a layer of high cloud, killing the contrast and the seeing is not steady. Jupiter is still quite low which doesn't help.

[Tropo-Bob]

Jeff, I persisted with small breaks in the clouds to the moment of panic when I felt rain drops on my arm. Fortunately, when I checked, none were on the lens. However, during that examination, my mount was slightly rained upon. Not the best start with trying out a new scope; a 4" F11. I saw Calistro in transit torwards the end, but missed the shadow.

[Saturnine]

Bob
Not the best start with trying out a new scope; a 4" F11. I saw Calistro in transit torwards the end, but missed the shadow.[/QUOTE]

That's a nice looking gear, quick an easy to set up by the looks of it, pity about the raindrops spoiling the session though.
Did manage to get a long look at the transit with my 127mm F8 achro and alt /az mount when the cloud thinned out for a while. Could clearly see the Red Spot and the shadow of Callisto but not the disc of the moon itself at 125X. Seeing didn't warrant pushing the mag much higher, just got fuzzier.
Now the S.E. coast is set for a drenching next week so no more astro for a while it seems.
I have noted that there will be another chance to watch a Callisto and shadow transit, in August 28th / 29th. Ingress at 22:50 and egress at 03:07 EST.

Cheers

[Tinderboxsky]

We had a fabulously clear sky here last night and I was fortunate to be able to view the Callisto moon and shadow transit once Jupiter had reached a reasonable elevation.
Callisto was at about mid transit and presented as a tiny dark disc standing out against the bright Jupiter surface. The shadow was a sharp black spot preceding Callisto as they transited across the face of Jupiter. The background detail on Jupiter was stunning.
I spent time at the eyepiece watching the shadow approach Jupiter’s limb, touch the limb and then form a notch in the limb. This notch slowly reduced and then disappeared. I tried for the same with Callisto but it became very difficult to see as it got very close to the limb. I could clearly see Callisto emerge from the limb as a small bright bulge. Eventually there was separation and the event was over.
This event has been a missing piece in my Jupiter observations. I have now seen all four moon+shadow transit events at last!
Vixen NA140SS on TRex mount and LVW5 - 160X.

[Saturnine]

Very nice report Steve, enjoyed reading that you had great views of the transit. Something that I can say as well is that I've now seen all 4 Galilean moon transits and imaged, though not good quality.
Am looking forward to the late August transit, from rough calcs. the planet should be about 50 deg altitude in the west at the start of the transit and getting lower to about 10/15 deg toward the end. Not ideal but they don't happen very often so gotta take what you get given, clear skies a must, of course.

Cheers

[Tropo-Bob]

Nice work Steve.