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Old 07-11-2010, 12:43 AM
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Join Date: Feb 2009
Location: Renmark, SA
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observing report 6/11/10

After playing with my secondary mirror trying to fine tune alignment for a few hours today it was pure luck it was clear to some extent tonight. I was planning mostly a planetary session as the satpic showed clouds enroaching, so probably would not have time for much deepsky viewing.

Time: 8:00pm-11pm
Scope: 12" F/4.4 truss dob
Seeing: variable from 2/10 to 6/10

No dew tonight, which was a relief after several frigid sodding wet nights this year.

Spent most of the night on Jupiter. At 8:10pm I caught the ingress of Io's shadow transit, with the moon itself visible as a dusky spot against the bright cloud tops of Jupiter. It seems whenever I turn the scope on Jupiter this season, I get treated to a shadow transit! Seeing was variable, ranging from terrifying to a short period of good seeing. During this time, I got some of the crispest views of the planet I've seen. At 256x, Lots of detail was seen in the NEB, but what surprised me was the SEB, which seems to be more obvious then in recent times. It appeared dull, dusky and even showed ruffling. The EQ zone of the planet seemed to be laced with faint, dusky streamers and several white ovals and zones. Spent a while on Jupiter, eventually seeing Io emerge from the transit followed by its shadow. Saw the GRS coming over the limb at about 11pm, but by then the seeing turned to absolute custard and was limited to under 200x.

I made use of this period of good seeing to check out Uranus. A nice crisp ball at 256x, infact I still got a nice well defined disk at 417x although it was blurring often due to seeing. I could see the moons Titania and Oberon. Best view of the moons was at high magnification.

I took a peek at 47 Tuc and NGC 362, both excellent at 417x, infact surprisingly crisp considering the variable seeing. NGC 362 was probably the best I've seen it, it just seemed more resolved than usual.

Also checked out M15, which, well was quite dissappointing, even compared to NGC 362! Damn, we are spoilt here in the southern hemisphere! At 166x, the outer 2/3rds was well resolved, but was faint compared to NGC 362. What surprised me, was that the view at 417x was superior to the 166x view....in this non-spectacular seeing. At this high mag, dozens of stars were resolved, all tightly packed condensing down to the hazy core.

Eventually the seeing turned to trash as some high cloud moved in at around 11pm, so called it quits. Was enthused to see stars focus down to pinpoints at 256x and still nice and tight at 400x+ while the seeing allowed. Looks like my secondary job paid off
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