Ordinary Meeting, 2005 January 26

 

The Sydney Observatory

Dr Lomb opened by asking how many members of the audience had visited the Sydney Observatory, and found that a considerable number had. He explained that historically, it had been founded in 1858, built next to Sydney harbour with the principal aim being that a time-ball should be placed on its roof, from where it would be visible to all shipping across the harbour. To this day, the panoramic view across the harbour from the top of the time-ball tower remained an exceptional sight. This foundation date was – the speaker added – very old by Australian standards, and placed it as the country's oldest observatory.

An impression of the Observatory from the late 1860s showed that, at this time, it had had a single observatory dome, with an attached residence for the Government Astronomer. In these early days, the principle telescope had been a transit instrument, though various other instruments were soon added to the collection, most notably the Schroeder 11.4-inch refractor, procured in 1872 by the then Government Astronomer, Mr Henry Russell. This telescope, now the oldest working instrument in the country, remained at the Observatory, and was still in regular use for public observing nights.

The speaker added that Russell had dedicated a great deal of attention to the transits of Venus of 1874 and 1882, and published his observations in a book in 1892. To commemorate this, the speaker showed the scene from the recent transit of 2004 June 8, which he added had attracted a great deal of interest, even though only the early stages had been visible from Australia. He remarked that it was curious that the black-drop effect was clearly observed from Sydney, although many UK observers had not seen it. Given that the Sun was low in the sky at the time of ingress in Sydney, this seemed to support the suggestion that it was predominately a seeing-related effect due to the Earth's atmosphere, rather than one due to the atmosphere of Venus or the Sun.

Moving on to the Observatory's present day activities, Dr Lomb described these as including the organisation of exhibitions and displays concerning its history, running workshops for local school groups and adult education programmes. In addition, there were frequent telescope viewing sessions, which combined the use of the historic Schroeder instrument with a recently acquired 16" Meade. However, the speaker regretted to report that the Association's New South Wales Branch had had a dwindling membership in recent years and, as a result, had decided that its name was excessively antiquated. Under its new name, the Sydney City Sky Watchers, it continued to hold monthly meetings at the Observatory. Dr Lomb also remarked that there was also a group based at the Observatory who were working to combat light pollution, and which was actively campaigning against any planning proposals which it was thought might significantly change the lighting conditions of the city.

To close, the speaker extended an invitation to all members to visit the Observatory, adding that they would be particularly welcome to join the Sydney City Sky Watchers' meetings on the evenings of the first Monday of each month. Concerning the light pollution issues raised in the talk, a member asked how Australian legislation in this regard compared with that in the UK. The speaker replied that Sydney was split into several municipal regions, and the situation varied between them. However, in the city centre, planning restrictions on lighting were comparatively favourable, though not all proposals complied with them.

The President then adjourned the Meeting until March 30, at the present venue.

Fairfield

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41.14°N
73.26°W
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