Word: pulsare
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Somewhat belatedly, Astronomer Anthony Hewish, leader of the Cambridge University group that discovered pulsars (TIME, March 15), revealed the positions and the pulse rates of pulsars 2, 3 and 4. One of them blips every 1.27 seconds, another at 1.19-second intervals-close to the 1.34-second period previously reported for pulsar 1. Pulsar 4 pulses significantly faster: every quarter of a second. In addition, Hewish estimated that the fast-pulsing source is only 50 light-years away, compared with the 200-light-year distance he calculated for pulsar...
Blue Star. Using the coordinates given by Hewish, Astronomer Frank Drake trained the giant Arecibo, Puerto Rico, radio telescope on pulsar 3 and discovered that each of its signals was composed of two closely spaced peaks. The peaks were so sharp, he said, that the signal may originate from an object as small as a few hundred miles across; if pulsar 3 were much larger, the peaks would be gradual and less distinct. Using England's Jodrell Bank radio telescope, Astronomer Graham Smith discovered that the radio waves from pulsars are polarized, indicating that they pass through a magnetic...
Checking on the faint blue star that Cambridge University astronomers have associated with pulsar 1, Astronomer William Liller located it on a number of Harvard Observatory photographs taken between 1897 and 1952. During that interval, he reported, the average visible light from the star had not varied significantly. And in California, Astronomer Allan Sandage announced that he plans to train the 200-in. Mount Palomar telescope on the blue star to detect any second-by-second variation in its light intensity that might coincide with pulsar 1's radio variation...
Meanwhile, pulsar theories continued to proliferate beyond the pulsating neutron-star and white-dwarf-star theories first suggested by Cambridge astronomers. Princeton Astrophysicist Jeremiah Ostriker suggested that the signals might be caused by rapidly rotating white dwarfs with a local disturbance on their surfaces. Signals from the disturbance would sweep across the earth like a lighthouse beacon once during each rotation of such a star. British Astrophysicists Fred Hoyle and J. Narlikar propose that the signals are connected with supernovas, or exploding stars...
...Oftentimes this intelligent-civilization bit has been overdone," says Astronomer Schmidt, "but if you want to attribute anything to a civilization, then this is the best case we have had so far." The chance that pulsar signals do come from an intelligent race, agrees Arecibo's Drake, "does remain a possibility." At week's end, Cambridge astronomers reported in a second Nature article that a faint blue star had been tentatively identified as one of the pulsars, providing still another clue that may eventually help solve astronomy's latest and most exciting enigma...