"Pulsars" is spelled using the IPA phonetic transcription as /ˈpʌlsɑːrz/. The word is a combination of "pulsating" and "stars," referring to highly magnetized rotating neutron stars that emit beams of electromagnetic radiation. The spelling reflects the stress on the first syllable ("PUL-sars") and the presence of the vowel sound /ʌ/ in the first syllable and /ɑː/ in the second syllable. The "s" at the end of the word denotes the plural form of "pulsar."
Pulsars are celestial objects that are characterized by their highly regular and rapid pulses of electromagnetic radiation. These objects are typically located in the depths of space and emit radio waves along with other forms of electromagnetic radiation. They are believed to be the remnants of massive stars that have undergone a supernova explosion.
The term "pulsar" is derived from the words "pulsating star," which accurately describes the pulsating nature of these objects. The pulses emitted by pulsars occur at incredibly precise intervals, ranging from milliseconds to seconds, and are incredibly stable. This stability and regularity make pulsars highly useful for a variety of scientific studies.
The mechanism behind the pulsating behavior of these objects is thought to be associated with their fast rotation and extremely strong magnetic fields, which are millions of times stronger than Earth's magnetic field. As the pulsar spins, beams of electromagnetic radiation are emitted from its magnetic poles, sweeping across space like the beams from a lighthouse. When one of these beams intersects with Earth's line of sight, it appears as a pulse of radiation.
Pulsars have proven to be valuable tools in various fields of astrophysics. Their precise periodicity allows astronomers to study the effects of space-time curvature, test theories of gravity, and even detect gravitational waves. Additionally, pulsars have been used to research the interstellar medium, neutron star physics, and the study of general relativity. With their unique properties and behavior, pulsars continue to provide valuable insights into the nature of our universe.
The word "pulsar" is derived from two terms: "pulsating" and "quasar".
In the late 1960s, the astronomers Jocelyn Bell Burnell and Antony Hewish discovered a strange astronomical phenomenon which they described as periodic pulses of radio waves. They initially labeled these sources "LGM" for "Little Green Men", humorously considering the possibility of extraterrestrial origin.
However, Burnell and Hewish quickly realized that these signals were of natural origin and not of alien nature. As they continued their research, they renamed these objects "pulsars" to reflect their pulsating nature.
The term "quasar", which refers to an extremely luminous and distant celestial object, was coined in 1963.