Partly cloudy skies greeted 12 visitors (10 students and 2 teachers) from The London School, Grades 8, 9 and 11, for Exploring the Stars at Western University’s Cronyn Observatory, Tuesday, November 7th, 2017, 12:00 Noon—2:00 p.m. Graduate student Viraja Khatu presented the digital slide presentation “Black Holes” and fielded questions. Viraja followed this with the “Crater Experiment” activity, which involved dropping various size balls into a pan—placed on the floor—filled with chocolate powder to demonstrate impact cratering.
Viraja had set up the observatory’s 90mm Coronado H-alpha solar telescope on the Sky-Watcher EQ5 equatorial mount on the observation deck outside the dome. RASC London Centre member Bob Duff centered the Sun in the field of view of the 90mm Coronado, using the CEMAX 25mm eyepiece (32X), and then swapped in the 18mm (44X) and 12mm (66.7X) CEMAX eyepieces for a better view of prominences and filaments on the Sun. However, clouds periodically obscured the Sun, which was eventually completely clouded out by the time the visitors arrived in the dome.
Bob gave a talk on the history of the Cronyn Observatory and the technical aspects of the big 25.4cm refractor in the dome as well how the London Centre’s 25.4cm Dobsonian reflector telescope and the 90mm Coronado H-alpha solar telescope worked. Since the cloudy sky ruled out observing the Sun through the 90 mm Coronado, Viraja and Bob directed the 25.4cm refractor (32mm Erfle eyepiece, 137X) to show the visitors the communications tower in south London.
Viraja then brought the visitors downstairs into the “Black Room,” where she showed them the “Spectroscopy Demo,” inviting the visitors to put on diffraction grating glasses and view the spectra of 4 gas discharge lamps set up on the table, including: hydrogen, helium, neon and mercury. The visitors were gone by around 2:00 p.m. after an interesting afternoon black holes, impact craters, telescopes, solar observing and spectroscopy, despite the cloudy sky.