STEMFEST outreach - the solar spectra

Peter Osman, Elizabeth Budek, Elizabeth Cocking and Toner Stevenson at Waverley STEMFEST, 22 May 2026.

Sunday 24 May, Sydney City Skywatchers volunteered at Waverley Public School's STEMFEST. Elizabeth Cocking was prime organiser and, with Peter Osman, Elizabeth Budek and myself, we had a very busy time as over 3,500 people, mostly primary school children with their parents, attended. We were in good company with the University of New South Wales 'Future Now' team and WIRES as neighbours, University of Sydney Engineers, who took a great interest in Peter's spectroscopy set-up, the Women in STEM, biologists, earth scientists, and many other organisations involved in STEM.

Peter Osman showing his spectroscopic imaging and Elizabeth Cocking. Photo: T. Stevenson 2026.

The highlight of the day was Peter's spectroscope. The sunlight reflected by the clouded sky into his telescope was dispersed through a grating, and into a colour digital camera. The spectrum was transmitted to Peter's ipad and laptop and we could see the dark Fraunhofer lines indicating the chemical composition of the light.

A small (not to scale) model of the solar system, and posters were of interest, and the Elizabeths told people about the Moons of Jupiter (over 100 at last count) and the other two planets, Venus and Mercury, that are able to be seen naked eye in the night sky during winter.

Despite the rain and clouds I managed to use my white-light filter telescope for about 10 minutes and myself and a few primary school-age keen observers saw many sunspots (I estimated 8) on our closest star, the Sun. The rest of the time we viewed distant objects.

A big thank you to the organisers of Waverley public school STEMFEST for a very well-organised and interesting day and to all the terrific parents who engage their children in science (and as we saw sometimes it's the children who engage the parents!).