George Ellery Hale. American astronomer George Ellery Hale (1868-1938) working in his Mount Wilson observatory near Los Angeles,USA. Hale is using an 18 metre high spectroheliograph to study the surface of the Sun. This instrument,which Hale himself invented,is capable of photographing the Sun at precise wavelengths and is now a basic tool of solar astronomy. Hale studied sunspots and discovered that they possess strong magnetic fields the polarity of which reverse on a 23-year cycle. Hale spent a lot of time persuading various bodies to fund the building of larger telescopes,including the 5 metre reflector at Mount Palomar,USA | |
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