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Old 29-08-2007, 10:09 PM
Its only a column of dust

žAB is offline
Join Date: Aug 2007
Location: New Iceland
Posts: 761
Jupiter obs report 29/8

well I touched up my collimation, which incidentally took half an hour and was very frustrating - I just couldnt get the hole to go into the middle of the out-of-focus star no matter how much i turned the collimation screws I was about to pull my hair out!

When I finally got it, the end result was quite good actually the out of focus star had the hole at or very nearly at the center.

It was a clear evening, seemed a little hazy though with only light dew and temps aroud the 10║C mark. Instrument used was Meade Ds114 114mm reflector and 7.5 and 5.5mm Plossl eyepieces.

Jupiter was once again above my rooftop, at approx 40║ altitude. Seeing was pretty good, perhaps a 7/10. Left the scope to cool for about an hour and got down to business. At 121x, the view was lovely, the GRS was clearly visible and sported a salmon pink colour, and using averted vision and patience, festoons and streamers were flickering in 'n' out of view. Spotted a couple of white ovals nested beneath the southern edge of the NEB. Encouraged by this result, I decided to pump it up to 165x but the disk became slightly fuzzier and generally not as well defined. "Sky and Telescope" says the recommended max magnification for Jupiter observing is 25-30x aperture in good seeing. At 165x I was pushing 37x per inch so I stepped beyond the recommended limit. Backing it down to 121x, or 27x per inch of aperture the view was again more pleasant. Even at this magnification it is within the recommended limits for Jupiter. Witnessed a satellite emerging from the eastern limb while at the same time a shadow transit commenced from the western Limb! What a treat! The black dot was ever so small and the contrast between it and the great brilliance of the planet itself made it quite challenging.

Not a bad result IMO, considering the full moonlight and Jupiter's position some 10║ from my heat storing rooftop and hot water boiler lol

The view was as good as one could expect, and after 7 years of loyal service, the DS reflector has still got it!

Last edited by žAB; 29-08-2007 at 10:24 PM.
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