Dead men may not tell any tales, but dead stars certainly do. The dead stars known as pulsars tell us about the how the stars lived and died, and about the odd physics of the corpses themselves. But they also tell us much more.
A pulsar is the remnant of a once — mighty star that exploded as a supernova. The star’s core collapsed to form a neutron star — a ball of matter that’s several times heavier than the Sun, but only as big as a city.
Many neutron stars rotate rapidly, sending out pulses of energy. Radio telescopes see these as rapidly flickering beacons known as pulsars.
Pulsars help astronomers understand more about the massive stars that gave birth to the pulsars, how the stars exploded, and the aftermath of those blasts. Astronomers also use them to probe the gas and dust between the stars.
The rate at which a pulsar spins is extremely stable, and astronomers are using that for several purposes. One is to look for gravitational waves, which are ripples in space caused by the motions of massive objects. Fluctuations of a few billionths of a second in a pulsar’s timing could be caused by these waves, which have not yet been discovered.
A pulsar’s accuracy also makes it a great clock. In fact, networks of pulsars could someday be used to provide even better timekeeping than that provided by today’s atomic clocks. And spacecraft could use pulsars as navigational beacons — letting dead stars guide them through the solar system.
Script by Damond Benningfield, Copyright 2013
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