Used with
permission of Maiken Naylor, University at Buffalo, Buffalo, NY, USA,
http://ublib.buffalo.edu/libraries/units/sel/exhibits/stamps
Radioastronomer Antony Hewlish (1924- ) and his graduate student Jocelyn Bell discovered radio sources in space that were called pulsars, because of their regular emission of pulsed energy. This confirmed the existence of neutron stars, extremely dense c ollapsed stars at the center of the pulsars which are highly magnetized. He shared the 1974 Nobel prize in physics with Martin Ryle (1918-1984), who was recognized for his achievements in radiotelescope construction. Known as the aperture synthesis techni que, this method employs several small telescopes deployed over a distance of about three miles whose positions are mutually adjustable and who act as one enormous composite telescope of corresponding size. The Ryle stamp shows two symbolic radiotelescop es receiving radiation from a radiogalaxy. The Hewish stamp shows a stylized pulse signal superimposed on the Crab Nebula, a supernova remnant which was first observed by Chinese astronomers in the 11th century, and which has a pulsar emitting energy burs ts across the whole spectrum at its center. The five stamps of this stunning 1987 Swedish set vary in color from a deep blue to black, like the night sky.