Quote:
Originally Posted by tonybarry
There was considerable interest in this occultation of Saturn in our local club (WSAAG), and four members attended UWS Nepean Observatory from 8am to setup and if possible observe the occultation. There was a 12" Lightbridge with several eyepieces and a polarising filter; a 10" LX200 GPS, and an LX90-10 with a Flea 3 camera.
The weather was particularly dodgy, with some large patches of blue sky that came and went in quick succession, along with a lot of cloud and some glare.
Alignment of the Goto scopes was done using terrestrial references (level and north) and this was good enough to get tracking on brighter objects (the Moon, Rigel Kent, Saturn).
However the target planet was invisible visually, and only with some serious histogram expansion was it visible in the camera using an IR pass filter and a gamma of 2.5. The clouds obscured the Moon for the disappearance, and an inconvenient tree on the UWS property threatened the reappearance. The scope / cam was moved but tracking was not able to continue and the reappearance was not observed either.
The occultation was therefore not observed.
None of the communications (in AS&T, or online) made much mention of the difficulty of the observation, and in my opinion, observation of this occultation was not possible due to the lack of contrast of the target against the bright sky. It was however a valuable lesson in what can and cannot be done.
Attached is one small cropped image of Saturn at 9:35am between breaks in the cloud, and a shot of the terminator of the Moon at the same focal length (2500mm). From left to right, the three craters are Arzachel, Alpetragius, and Alphonsus. The improvement in contrast is due to the relative magnitudes - the Moon is mag -6 (apx) while Saturn is mag +0.6 (and Titan, the brightest moon of Saturn, is mag +9).
It is safe to say that this represents the most challenging occultation I have attended.
Regards,
Tony Barry
|
Hmmm, maybe my shots aren't such a stuff-up after all...
Haven't seen any other shots of the re-appearance yet but Colin Legg got some crackers of the disappearance.
Cheers -