Public Lectures for the Session 2002-2003 held in Room E7 of the Renold Building, UMIST.
Delivered to the Manchester Astronomical Society

17th October 2002

''The Sun in History, Art and Science''

Prof. John Parkinson
Sheffield Hallam University.

The story of the sun is timeless; a star taken for granted but upon which all life on earth depended.

Professor Parkinson first took us back to the days of the Egyptian Dynasties when in the 14th century BC, Pharaoh Akhenaten, transformed the Ra cult into the royal worship of the sun-disk, Aten. The Greeks worshipped Helios, and thereafter sun worship is found worldwide, in Mexico, India, China and Korea. Each culture had its own sun deities.

However, the Earth was the center of the Ptolemaic universe. The sun was subservient and orbited the classical Greek world. It was Copernicus who first set the sun as the center of the modern planetary system, later to be justified by Kepler and then quantified by Newton.

John Parkinson then took us through a portfolio of various depictions of the sun in Renaissance fine art. Its image was also used to ward off evil spirits in Medieval Europe and is still drawn on the prows of boats as heavenly protection.

Now, thanks to the astrophysics developed in Europe and Britain during the 19th and early 20th centuries, we know the sun to be a close-by but otherwise fairly typical star. It is very round, shows limb darkening characteristic of a gaseous body and sunspots occasionally mar its surface. These are centers of magnetic activity where internal magnetic field lines break though the otherwise uniformly bright surface to give localised cool spots darker in colour. Observing the sun in the light of different spectral regions gives important information about the star in various temperature regimes and heights above this photosphere.

Prof. Parkinson rounded off his talk with reference to solar eclipses. These gave him an invaluable opportunity to observe first hand the elusive solar corona and other transient phenomena. He was particularly interested in the notion that the solar radius might vary throughout the sunspot cycle or over long periods of time but this was as yet unverifiable. He entertained us with reminiscences of the clouded out eclipse from Cornwall in 1999 when he was part of the BBCs anchor team and he looks forward to his next eclipse expedition, to the Antarctic and the first ever observations of a total eclipse of the sun from this remote land.

Synopsis by Kevin J. Kilburn (Secretary)

Maintained by Michael Oates
Page modified 28 October, 2006