Auke Slotegraaf – visit to the Hermanus Centre of the ASSA

Members making their Southern Star Wheels under Auke’s tutelage

Report back from Auke Slotegraaf  – extracted from his website

From September 24 to 26 I visited the Hermanus Centre of the ASSA to give a talk at their monthly meeting and to present two workshops.

This vibrant Centre is driven by a number of enthusiastic individuals, and it is always a joy to be immersed in such a dynamic setting.

I was graciously hosted by Steve, Meg and Auntie Kleyn; I first met Steve many moons ago at the Cape Centre and have frequently retold the story of his mirror grinding Heath Robinson device made from a washing machine.

Hermanus is without a doubt my second-favourite town, although it is now a very different place from the one I fondly remember from back in the good-old-bad-old days of the 80s. Lots of things have changed and lots have stayed the same. I watched Sparks watching a group of aspirant surf-life savers making the cold tricky trip around Voelklip, and the restaurant along 10th street was still tightly shut. Grotto Beach’s delightful camping spot no longer hosts life-changing New Year’s parties. Niel du Toit’s shop still sells everything you need, and when the wind blows, your Zippo is definitely not wind-proof as the box advertizes.

The very popular Whale Festival was on in full force at this time, so the town was even more traffic-logged than usual, with an inordinate number of traffic wardens and speed cops in attendance.

The first event, on Thursday the 24th, was the Centre’s monthly meeting, held at Fernkloof, another well-explored haunt in my past. I shared some interesting facts about the fascinating lives of three early scientists – Tycho Brahe, Johannes Kepler and Galileo Galilei. One of the interesting questions I tried to field after the talk was about Catholic doctrine: when did it become officially OK to accept that the Sun was at the centre of our solar system? I’ve subsequently done a bit of digging, and the answer seems to be (incredibly) September 11, 1822! On that day, the College of Cardinals announced that “the printing and publication of works treating of the motion of the Earth and the stability of the Sun, in accordance with the opinion of modern astronomers, is permitted.”

Friday evening’s event, also at Fernkloof, was a practical affair: making and using the Southern Star Wheel. Some 24 cut-and-pasters deftly assembled their planispheres, and a few tips on its use were discussed.

Assembling Star Wheels



Andrew Brink floored me with his question: how old is this technology? While I have a few books on celestial cartography, none of them mention planispheres in the form we know them today. I took a wild guess: 150 years old?

The final presentation was held in the well-appointed lecture room of the Hermanus Magnetic Observatory, one of the national facilities of the NRF.

Early attendees at the deep sky workshop at HMO

I was surprised at the good turn-out, since today’s was a specialized topic: a deep sky observing workshop. I spoke a bit about cognition and perception, gave a brief history of observations of the “nebulae”, and a few practical exercises were done. The results of these exercises will be added to those collected at previous workshops for analysis and publication. Lunch followed the close of the workshop, heralding the start of the good-byes and the traffic-congested trip home.

See you soon, Hermanus!

Special thanks to my points-of-contact (Steve, John Saunders and Pierre de Villiers) and the members of the Hermanus Centre who made the three days a most enjoyable experience.

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