What did you see tonight?

[John]

54 minutes ago, Stu said:

There’s a fairly uncommon Ganymede transit coming up which I posted about a while ago. In theory Ganymede is a bit darker than Io or Europa so may show as dark against Jupiter and so be visible more easily during its transit. Cloudy here inevitably 🤬

It's still nice and clear here but will it last ???? 😬

[Stu]

Just now, John said:

It's still nice and clear here but will it last ???? 😬

🤞🤞🤞

[wookie1965]

I've got this I need to move. 

[PeterStudz]

Despite the forecast it’s clear here in Southampton. Although tonight we’ve arranged to go out with friends for dinner. Typical! But shouldn’t complain. Hopefully it’ll still be clever when I eventually get back. 

[Ratlet]

First clear night in weeks and I've been laid up with some mystery stomach bug.  Hopefully it will clear up quick and tomorrow is clear.

[John]

1 hour ago, Stu said:

🤞🤞🤞

Still lovely here - very good views as Ganymede starts it's transit 🙂

[JeremyS]

Just come into warm up.  Even out in the obsy since 17.15 👍🏻👍🏻👍🏻

[Stu]

5 minutes ago, John said:

Still lovely here - very good views as Ganymede starts it's transit 🙂

Good stuff, cloudy here 😞

So, is Ganymede appearing bright or dark against the surface? Probably bright just to prove I was talking twaddle all along 🤣

[Stu]

Typical! I’ve just let the dog out and the sky is now stunningly clear! We are in the middle of a film though, so no chance of going out now unfortunately.

[John]

13 minutes ago, Stu said:

Good stuff, cloudy here 😞

So, is Ganymede appearing bright or dark against the surface? Probably bright just to prove I was talking twaddle all along 🤣

It's bright currently (sorry Stu !). Brighter than the background cloud tops. It's transit is across Jupiter's far southern polar zone though, which is a bit darker than the STZ to the north of it. Europa is going to start it's transit at 22:02 but further north so it will be interesting to see how that appears.

Edited January 6 by John

[Pixies]

Io will be vanishing behind Jupiter in about an hour. You should be able to see it vanish while both Europa and Ganymede are transiting. In fact, Io will disappear just minutes before Ganymede clears.

Still nice a clear here. I've got the dob out cooling, so fingers crossed. I haven't done any observing  in months!

[SwiMatt]

I just came back from my usual spot in the forest, but tonight it was way too cold for me. I gave up after 50 minutes in the snow at -12°C.

I did catch some beautiful views of M42 and of the Christmas Tree Cluster, as well as some details on the surface of Jupiter.

The trapezium in M42 was so neat at 166x, stunning view. Can't wait to get out and sketch that (once it gets warmer...). I spent most of the evening on that.

The Christmas Tree was a first, it took me some exploration to find it since Monoceros was completely invisible - I had to triangulate with Orion, Gemini and Procyon, it took some estimation and ingenuity. Very nice cluster!

I did not see the transit (or better, I did not notice it), but the equatorial bands were very sharp and they were showing some dark puffs. Cool stuff.

[John]

Clouds have now intervened with the observing, annoyingly.

I got as far as Europa just starting it's transit and still visible against Jupiter's limb, as is often the case with such events. My guess is that Europa will quickly become very tricky to see against Jupiter's surface as it moves across the disk.

Ganymede was visible as a bright spot for at least 50% of it's transit but has now become very tricky to see. 

I suppose the moon's illumination by the sun can vary slightly as it moves in it's orbit and the angle of solar illumination, relative to our vantage point changes. It may also be (likely, really) that Jupiter's south polar region is not an even albedo across the diameter of the planet so the visibility of a transiting moon against it will change as the transit progresses.

All interesting stuff and very enjoyable to watch. One effect that was noticeable to me tonight was shortly after Ganymede started it's transit and while clearly visible against Jupiter's southern cloud tops was that both the moon and Jupiter seemed to "pop" into 3D. They both looked like the spherical objects they are with one in orbit around the other. The solar system in action in real time 😁

 

Edited January 6 by John

[Mr Spock]

Non stop cloud here 

[bosun21]

I had a couple of hours of partially clear skies so I rather hastily wheeled the new dob outside to try and capture some images of Jupiter. It’s really cold here and my fingers were numbing up quickly. I had to align a Baader RDF on Jupiter which isn’t that easy with a new go to dobsonian. It took me longer than I would have liked to centre Jupiter in the eyepiece and adjust the RDF to the planet also. Got the laptop and camera, ADC all set up with Jupiter in the centre of my screen. Just about to start capturing the videos and my newly fitted Electric focuser completely jammed!!. I tried to fix it on site, but to no avail. My fingers were numb so I had no intention of fiddling with screws and Allen keys in the dark. I had to abandon everything and head back indoors. To make things worse I managed to free the focuser in roughly 5 seconds when back inside. I had the draw tube fully drawn in when it seized for some reason. I can’t get this to repeat after many full range movements. So my lessons learned is that Sod’s law is very real and secondly I just have to get a G&G set up.

[Zermelo]

As Stu said, it was cloudy for hours here, then on my last check it was suddenly clear, so I managed to get half an hour in before the entire sky has just clouded out.

I watched the action at Jupiter, and it was well worth seeing. One moon, Io I think, was quite close to the disc, North of the equator, and I watched as another (Europa?) approached the other limb, to the South, and disappeared behind it. I think Ganymede was probably transiting already and I didn't spot it.

Conditions weren't perfect, but the NEB and SEB were showing quite a bit of detail. I was trying out a Svbony SV135 zoom for the first time (Christmas present), and I could take it up to about x150 (10mm in the Mak) without the image degrading. That was convenient to compare it againt my gold standard, the BCO 10mm. I could see no difference.

[Alan White]

I have been sat with the family watching a very odd film, but family time, which was great.

Just locking up and it’s clear, so had a quick 20 mins with the binos, wonderful, glad I did.

[John]

The clouds have cleared away here so I have managed a bonus view of Jupiter just before it dipped below the roofline of our house.

Ganymede was just starting to exit the jovian planetary disk so there was a slight "bump" on the western limb but otherwise I was presented with the unfamiliar sight of Jupiter sporting just the one Galilean moon (Callisto) with Io having moved behind it's parent planet.

Europa was well in transit and not visible to me against Jupiter's disk.

Looking at some of Orion's binary stars, the seeing seems to have gone downhill somewhat so I doubt that Sirius B will b "on" tonight. I might give it a try anyway though 🙄 

Edited January 6 by John

[Zermelo]

I went out for a final attempt, and in some sucker holes I managed to see Ganymede just appearing from behind Jupiter. A frustrating evening, but worth setting up, just for the Jovian dynamics.

[Nigella Bryant]

Just in after a four hour stint on Jupiter. Fairly well defined features this evening. 8pm showed the NEB with two large blue festoons going into the Eqzone. At the northern region of the NEB was what looked like three white ovals. SEB at this time looked fairly bland but with several knots on the southern part. 

By around 9.30pm there appeared a festoon to the South East of the SEB. Observed Io disappear behind Jupiter later and Europa and Ganymede transiting the Southern Tropical zone area. 

A great evening. 

[Pixies]

First proper session in months. Not sure why the break, I just seemed to lose my mojo a little. Anyway, hopefully back now.. I had the 8" dob out in the back garden. Sky was clear and dark for here (at the start anyway). Seeing average. The transparency worsened over the session and by midnight it was cold, damp and the sky was getting a little milky.

Started with Jupiter. However, it was getting lower in the sky by the time I started and pretty wobbly. Saw Io vanish behind and Ganymede finished its transit and appeared like a little pimple. No sign of it before and nothing of Europa.

Then on to the Orion Nebula. One of the better views I've had from the back garden. Using the Vixen LVW 22mm it was well framed, but with the 13mm Nagler I could see the 'marbled' structure around the trapezium and dark lanes. The UHC and Oiii filters brought out the further reaches of the nebula, but I preferred the clear bright views without. No sign of any of the fainter trapezium stars. Spent a good hour on this alone.

M35 filled the view in the 22mm. Nearby NGC 2158 was just visible - the first time I've seen it from the garden.

M1 was hard to see. The transparency was getting worse now.

Finished on Beta Monocerotis. Never observed this before (saw it mentioned a wee while ago). Very pretty at around 100x - no discernible colours.

 

A neighbour then hit the lights, so I called it a night.

[GrumpiusMaximus]

My Dad was running a session with his mate with a 20" reflector at an observatory local to him.  I'll have to ask him what he saw but I am incredibly jealous.  I left my scope outside after my earlier 10 minutes or so on Jupiter, optimistically thinking it might clear up.  Came back outside an hour later to discover that leaving my scope out had angered the cloud Gods and it had rained.  No damage done fortunately.  Checked every half hour for a break or so but no luck.

No doubt the minute I'm asleep my town will magically become a Bortle 1 zone with perfect seeing and I'll also miss a bolide.  Or something.

[Telescope40]

Hello all. Got a session in yesterday. Out about 4 pm with my Tak 128. Jupiter first up in the gathering twilight. Very steady and great viewing of the GRS transit. Was it me, probably, but I did seem to notice the SEB was markedly different preceding and following the GRS. The band after the GRS looked rather washed out and indistinct compared with the band ahead of the spot ??  

Came in about 5 pm for food and back out again. Jupiter for another period of time and then a scoot around some usual suspects with the aid of SS. M34 M35 M36 M37 M15. Finished off with a new open cluster to me - NGC 752 in Andromeda. Rather chuffed.  Clouds beginning to spoil the party at this point so packed up about 8 pm. 

John 

[Stu]

3 hours ago, Telescope40 said:

Was it me, probably, but I did seem to notice the SEB was markedly different preceding and following the GRS. The band after the GRS looked rather washed out and indistinct compared with the band ahead of the spot ??  

Yes, that’s what I’ve been seeing. The turbulence of the GRS seems to split the SEB then trailing it there is a dark band but at the bottom of GRS. @John’s sketch here shows it well I think.

 

[Nigella Bryant]

3 hours ago, Telescope40 said:

Hello all. Got a session in yesterday. Out about 4 pm with my Tak 128. Jupiter first up in the gathering twilight. Very steady and great viewing of the GRS transit. Was it me, probably, but I did seem to notice the SEB was markedly different preceding and following the GRS. The band after the GRS looked rather washed out and indistinct compared with the band ahead of the spot ??  

Came in about 5 pm for food and back out again. Jupiter for another period of time and then a scoot around some usual suspects with the aid of SS. M34 M35 M36 M37 M15. Finished off with a new open cluster to me - NGC 752 in Andromeda. Rather chuffed.  Clouds beginning to spoil the party at this point so packed up about 8 pm. 

John 

Yes, you're right John, the GRS is disturbing the SEB. My image taken in December highlights this.