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A Sun Day Out

Roger North & his telescope

Are you young enough to remember your mother's warnings about watching solar eclipses with the naked eye—or even through smoked glass? How often did she warn you that, "If you do that, you'll go blind!"  Well, as is so often the case, Mum was right. Sun gazers are at risk of major eye problems and need to take care. Of course you could always pop down to your local optician and buy a filter for around $4000, or you could try using somebody else's filter.

U3A members were treated to just such an opportunity in December when Tony Bayes organised an end-of-the-year visit to Wentworth Falls Observatory to watch the sun from Roger North's magnificent observatory.

During an instructive talk by Tony we learned about Lagrangian Points, located about 1.5m kilometres toward the Sun (about a tenth of the distance between Earth and the Sun) where the two bodies exert equal and opposite gravitational pull. That's where SOHO has been located. No, I don't mean Soho, London – it's the acronym for SOlar and Heliospheric Observatory. SOHO is a spacecraft that was launched in December 1995 to study the sun. Originally planned as a two-year mission, it is still operational after eleven years in space.

The talk was so interesting that I was a little disappointed when Roger came in to tell us he had been setting up the telescope and that there was a sun-spot three times the Earth's diameter clearly visible on its surface. Since cloud was threatening, the talk had to be abandoned while we all went to see.

We spent the rest of our visit taking turns to look at the Sun through two telescopes with two different types of filter. In addition to the big sun spot we also saw prominences around the perimeter. These were things I'd heard about, and seen in photographs, but had never had the opportunity to observe first hand. It was quite an experience!

Afterwards, we enjoyed a picnic lunch and I think everybody will visit the observatory again.

Roger offers Sun viewing during the day for $5/session, and night viewing for $10. Personally I'm going to wait until winter when the night air is crisper and the viewing even clearer.

If you would like to visit the Observatory, why not telephone Roger North or Sybil Barber at 4757 2954 or email them at north.barber@optusnet.com.au. The observatory, located on Kings Tableland, Wentworth Falls, is open on Friday, Saturday and Sunday evenings from 7.00 pm (8.00 pm daylight saving time) but group bookings can be arranged on Wednesday or Thursday evenings.

              —David Evans

Wentworth Falls Observatory

Inside the Dome