PDA

View Full Version here: : Jupiter Sketch and Uranus 12/8/11


pgc hunter
12-08-2011, 12:48 PM
Observed Uranus and Jupiter this morning. Forecasts were favourable for good seeing, so went to bed straight after work, set the alarm for 3am (I actually can wake up if its to do something I enjoy :D ) I took the scope out after I got back from work so by the time I began the session it has been cooling for nearly 4 hours.

Seeing proved to be very good. Uranus was excellent, but by the time I got to Jupiter, it seemed to be patchy but still managed some nice views. The defocused image of Jupiter still boiled a bit, so clearly it could've been better.

Scope: 8" F/6 dob
Time: 3am- sunrise
Seeing: up to 8/10


Started with Uranus. Seeing was good enough that I could use 375x on the 8" dob with a nice crisp greenish-blue disk. Some people claim they can see markings on Uranus, I couldn't see any, just a uniformly coloured disk. The planet was located on the 'border' of a triangle bounded by 3 stars.... looking it up in Cartes Du Ciel, it turns out one of these "stars" is actually Titania, presently at mag 14.0! Not bad considering the moonlight and only 8" aperture. Difficult to glimpse ofcourse, but at 480x the moon was held quite easily when concentrating on the area.

By the time I got to Jupiter, seeing was a bit more sketchy with some rough periods, but seemed to calm down towards sunrise when a fair bit of very low contrast festoon activity in the EZ popped in and out of view. Fairly crisp image at 240x. The moons were obvious disks, with Io showing a ruddy orange type colour. The SEB was notably broad and diffuse unlike in recent years.

We'll let my sketch do the rest of the talking :)

details ... start 5:35am / Finish 5:50am, (19.35/19.50 UT)

Telescope: 8" F/6 dob
Magnification: 240x
Seeing: 7/10

mental4astro
12-08-2011, 03:00 PM
Sab, that is a really good sketch, mate. Very nice observation of Jupiter. I really, really like the 8" f/6 scope combination for the planets. Not too bright to create too much glare, and big enough to be able to rip out a lot of detail. I haven't aimed my scopes at these targets yet this season. You've managed to score a very good night for some real high power observing!

To see any type of detail on Uranus, I would imagine you would need to be at a very high elevation, and have very good optics at your disposal. Not an object that would reveal too much anyway from our vantage point. At most, faint variations in the light and dark cloud formations. But Titania! Way to go again, Sab! Your next sketch should be two of Uranus, showing Titania in different locations around the green giant, ;).

Have you tried for Neptune yet? I've seen it once through an 8" f/6 dob. Not much at all by way of a disk, but its very distinct blue colour is its real give-away.

orestis
12-08-2011, 05:16 PM
Nice sketch Sab :thumbsup:,

I have also heard and seen sketches of features on uranus,Which is quite amazing.

Thanks for posting
Regards Orestis:D

Paddy
12-08-2011, 10:24 PM
Nice sketch Sab. And well done spotting Titania - very impressive. I find it hard to imagine ever seeing detail on Uranus.

pgc hunter
13-08-2011, 12:38 PM
Thanks for the responses guys. Alex, this 8" F/6 is quick becoming my favourite weapon of choice - takes less than 5 mins to setup and tear down and the optics appear to be excellent. I haven't really observed Neptune yet, the few times I tried seeing was too poor to bother with.

I suppose seeing detail on Uranus is not out of the question, but seeing obviously has to be as perfect as possible, with dark skies and as high mag as practical.

Still surprised to have seen Titania, being mag 14 with a nearly full moon flooding the sky.

Here's a side by side of my field notes and a excerpt from Cartes Du Ciel.

DarkRevenge
26-08-2011, 04:15 AM
Really good sketch! Thanks a lot for sharing it.
I know this thread is some days old, but would you mind telling me what eyepieces were you using? I have bought a 10" F4.8 dob some weeks ago, and I'm trying to figure out what eyepieces I should buy :P

Cheers, Luis.