Occultations with my finderscopePosted By david elosser |
Last night, June 18th, I'm sure most of you got a chance to catch the lineup of Saturn, the crescent moon, and Venus. I decided to try something different. My Stellarvue F50 finderscope has eyepiece interchangeability. The 7th magnitude white dwarf HIP 45894 was going to be occulted by the dark side of the moon, so I put in a Meade 5000 series 5.5mm plossl. This gave me 36x. Image quality was very good, with no ghosts or glares to hinder me. With steady air, I could see 45894 with direct vision. The dark side of the moon was easily visible. I could put the sunlit side just out of the field of view to preserve dark adaptation. But as the occultation was about to happen, the air suddenly went bad on me. The white dwarf faded in and out so I could not catch the exact moment. Given the circumstances, I'm going to chalk this one up as a victory.
The air was steadier over Jupiter though. Around 10:20 EDT Io was about to be occulted by Jupiter. It was less than 3 arc seconds from the limb. I could see Io through the F50 as a bright dot just touching the limb of Jupiter. A few minutes later Io dissolved into Jupiter through the F50 so I switched to my SV102ABV to follow it the rest of the way. The air was mostly steady and at 128x through binoviewers I resolved Io into a tiny airy disc and watched it slowly disappear behind the gas giant. I looked down at my watch to record the time but Murphy was looking over my sholder again. The watch battery was too weak to illuminate the dial! :C Oh well! It was still a very rewarding evening.
David E
SV102ABV with Stellarvue F50 9x50 RACI

The air was steadier over Jupiter though. Around 10:20 EDT Io was about to be occulted by Jupiter. It was less than 3 arc seconds from the limb. I could see Io through the F50 as a bright dot just touching the limb of Jupiter. A few minutes later Io dissolved into Jupiter through the F50 so I switched to my SV102ABV to follow it the rest of the way. The air was mostly steady and at 128x through binoviewers I resolved Io into a tiny airy disc and watched it slowly disappear behind the gas giant. I looked down at my watch to record the time but Murphy was looking over my sholder again. The watch battery was too weak to illuminate the dial! :C Oh well! It was still a very rewarding evening.
David E
SV102ABV with Stellarvue F50 9x50 RACI