A partly cloudy, hazy, gradually clearing sky greeted 36 visitors (20 students and 16 adults) from the Louise Arbour French Immersion Public School Grade 6 class, for Exploring the Stars at Western University’s Cronyn Observatory, Thursday, June 7th, 2018, 8:00 p.m. Graduate student Viraja Khatu made the digital slide presentation “Black Holes” and fielded questions. Viraja followed this with the “Constellations” activity, distributing 33 “Star Finder” planispheres and showing the visitors how to assemble and use them to locate constellations in the sky.
Viraja then introduced RASC London member Bob Duff, who accompanied everybody downstairs into the “Black Room” where Viraja did the “Spectroscopy Demonstration,” with the visitors putting on diffraction grating glasses to view the spectra of 4 gas discharge lamps, including hydrogen, helium, neon and mercury.
Bob made ready the big 25.4cm refractor in the dome, installing the 32mm Erfle eyepiece. He was joined by Unattached RASC member Paul Kerans, who set up the London Centre’s home-built 30.5cm Dobsonian on the observation deck. Bob and Paul adjusted the collimation on the 30.5cm Dobsonian after Paul retrieved a collimation knob and reinstalled it on the back of the primary mirror. Bob gave Paul the Meade 28mm Super Wide Angle (54X) and 17mm Nagler (88X) eyepieces to see which would work best on Jupiter.
When everybody arrived upstairs in the dome, Bob gave a talk on some of the history of the observatory and technical aspects of the 25.4cm refractor. He also called their attention to the Schmidt camera and Cassegrain reflector telescope piggybacked on the 25.4cm refractor and explained the 2 clocks on the east wall and the difference between Standard and Sidereal Time.
Viraja directed the 25.4cm refractor towards Venus and supervised as the visitors climbed the observing ladder to view the planet through the 32mm Erfle eyepiece (137X). Since Jupiter looked good through the 30.5cm Dobsonian with the 17mm Nagler eyepiece (88X), Paul gave Bob the Meade 28mm SWA eyepiece for use with the 25.4cm refractor. Viraja swapped in the Meade 28mm SWA eyepiece (157X) for a better view of Venus and later Jupiter through the 25.4cm refractor.
The visitors were gone by around 10:00 p.m. after and enjoyable evening with the slide presentation “Black Holes,” assembling and using the “Star Finder” planispheres, the “Spectroscopy Demonstration,” and viewing Venus an Jupiter through telescopes.