| 单词 | pulsar |
| 释义 | pulsar (once / 59097 pages) n A pulsar is a small, dense star that emits a beam of electromagnetic radiation in a pulsing pattern as it rotates. Like a lighthouse light, the energy from a pulsar can be observed when it's pointing toward Earth. Astronomers discovered pulsars in the 1960s, and they're still not sure exactly how they emit such huge amounts of radiation. They do know that pulsars spin, and that the "pulses" of energy have regular, precise spaces between them. Some pulsars emit radio waves, while others produce gamma ray or x-ray wavelengths. Pulsar comes from "pulse" or "pulsating star," and is modeled after quasar. WORD FAMILYpulsar: pulsars USAGE EXAMPLESTo spot those waves, astronomers are turning to stellar timepieces called millisecond pulsars. Science Magazine(Dec 22, 2016) They can fly to Belgium and take a seat on the Mack Rides Pulsar, a roller coaster that splashes into a lake at 60 mph. Washington Post(Oct 28, 2016) The world’s largest radio telescope will catalog pulsars; probe gravitational waves, dark matter, and fast radio bursts; and listen for transmissions from alien civilizations. Science Magazine(Sep 26, 2016) n a degenerate neutron star; small and extremely dense; rotates very fast and emits regular pulses of polarized radiation Hyper neutron star a star that has collapsed under its own gravity; it is composed of neutrons |
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