Jump to content


Jupiter and the Great Red Spot (05/06/16) 21:00 - 23:30.


Recommended Posts

Telescope: Vixen FL102s
Vixen prism used (with hindsight should've swapped it for the Tak prism as better quality)
EPs used: Vixen Lanthanum 20mm (46x)and 5mm (184x), (again with hindsight should've tried a Tak LE 7.5mm (123x) and a Nagler 4.8mm
(192x) for comparison).
Conditions: Ant II - III
Target: Jupiter (36.7")

I was set up early in still in daylight at 21:00 with the sun still above the horizon. Although ClearOutside reported it as 'clear'
there were annoying patches of cloud right in the vicinity of where Jupiter was supposed to be which was annoying, but eventually
managed to spot it with binocs.

At 46x Jupiter looked super crisp as well as all four moons, was hoping one would be 'missing' so I could try and spot it or it's
shadow but was not to be tonight. Although have seen plenty of moon/shadow transits in the past. Banding on Jupiter was crisp and
obvious, very nice.

Jumped to 184x, and the edge of Jupiter was occasionally wavering but overall not too bad, could immediately see 4 dark belts
easily, the equatorials, which were a tanny brown in colour and the temperates, and in moments could detect more detail in the polar
regions. I suspected tonight that 184x might have been a tad too much for the conditions as occasionally clouds drifted by a few
times and I lost Jupiter and when they cleared I had to find it again.  Annoying!

Clouds were gone by around 22:00 (ish).

With this scope I have resolved Jupiter's moons as discs in the past when it has been more favourable, but due to their distance I
could detect an extremely faint first diffraction ring around Io and Europa, indicating sub-arcsec and unresolvable discs, I don't
recall seeing a diffraction ring around Ganymede as that was 1.4" and probably resolved (just) and Callisto was out of the view
almost all the time due to the power used (184x) and the FOV being too small. To be fair I was largely concentrating only on

I could see all the bands were uneven and in good moments could see a marbling effect of detail in the middle of the SEB and other
details on the southern edge of the NEB. During these moments details all over the globe was spotted/suspected and a few times
seeing clarified enough to me to utter "Nice!"

With hindsight I regret not taking notes/making a rudimentary sketch (very rudimentary LOL) to record some of the detail at the EP
so I could build up a 'picture' of detail and move on to the next feature spotted, as it was harder than I remembered it, oh for
younger eyes again ;)

At around 22:30 or maybe 22:35 (I looked down at my watch) I noted a circular indentation and the extreme edge of the globe in the
SEB, and it dawned on me, that's the GRS! Holy Sh*t! I didn't know that was going to make an appearance..that made my night and by
23:00 it was 'popping' out of the SEB like an eye, in good moments I could see some detail lightish/white (ish) markings around the
hollow preceding it and underneath it. I honestly didn't realise there was a GRS transit tonight and checking Stellarium as I write
this and backtracking the time the software shows the transit too, which shocked me as well, that's cool will be handy for checking
on it in future.

By 23:30 I was having to stand up to view as Jupiter's altitude was starting to drop, lifting the EP end and I was getting tired, so
decided to call it a night. It wasn't easy though, just one more glance for a chance to see more detail....but eventually I was
starting to feel uncomfortable and that was that.

Overall looking back and having written this report I saw a fair bit of detail, not bad for the first time back on Jupiter. Just
goes to show the value in notes and sketches and the wish for younger eyes! The GRS transit was a real bonus.



Link to comment
Share on other sites

Nice report Tony,

I had similar details in my Tak Fc100 last night though the seeing for me was not that great and was actually getting the nicest detail at 92.5 X with a Televue 8mm plossl (148X with a 5mm SLV was ok in the steadier moments)

I had looked on my Jupiter app what time the GRS was coming into view so wasn't quite such a surprise but was still nice to watch it from the discs edge moving across the planet.



Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.