Chapter 1
Introduction to the Pulsars
In 1967, Professor Antony Hewish and his student Jocelyn Bell at the University of
Cambridge coincidently discovered a flickering radio pulse source with a repetition
period of 1.3373 s, when they were investigating interplanetary scintillation. This
pulsating source of radio was then named pulsar. It was shown by the detailed investigation that the pulsar was just possibly the neutron star predicted hypothetically
by Lev D. Landau, a famous physicist from the Soviet Union, in 1932. The neutron
stars result from the supernova explosion of the massive stars after evolving very
long time and combining gravitational collapse, with a kind of extremely physical
environment, including an extremely high temperature, density, pressure, magnetic
field and gravitational field. Typically, they have a radius on the order of 10 km,
a mass between 1.44 and 3.2 solar masses and a core density up to 10
12 kg/cm
3 .
The pulsars belong to the neutron stars with very rapid rotation and have extremely
stable periodicity. Especially, the periodic change rates of millisecond pulsars can
get to 10
–19
−10
–21 s/s, and hereby the millisecond pulsars are known as the most
stable clocks in nature. The pulsars are not only very significant for the studies
on astronomy, astrophysics and cosmology but also have the potential application
values for high-energy physics, time–frequency science and space science. The X-ray
signals radiated from the pulsars can provide high-precision autonomous navigation
information for spacecrafts. So, the pulsars are able to become the lighthouses of
space flights for human beings.
1.1 Theoretically Predicted Neutron Stars
As everyone knows, the end of stellar evolution will produce finally compact stars,
including white dwarfs, neutron stars and black holes. The white dwarf was discovered empirically when scientists could not understand what are the celestial bodies
or the radiating sources, the neutron star was accidentally found on the basis of theoretical prediction, and the black hole has been investigating theoretically up to now.
© National Defense Industry Press and Springer Nature Singapore Pte Ltd. 2021
P. Shuai, Understanding Pulsars and Space Navigations, Navigation: Science
and Technology 11, https://doi.org/10.1007/978-981-16-1067-7_1
1
Introduction to the Pulsars
In 1967, Professor Antony Hewish and his student Jocelyn Bell at the University of
Cambridge coincidently discovered a flickering radio pulse source with a repetition
period of 1.3373 s, when they were investigating interplanetary scintillation. This
pulsating source of radio was then named pulsar. It was shown by the detailed investigation that the pulsar was just possibly the neutron star predicted hypothetically
by Lev D. Landau, a famous physicist from the Soviet Union, in 1932. The neutron
stars result from the supernova explosion of the massive stars after evolving very
long time and combining gravitational collapse, with a kind of extremely physical
environment, including an extremely high temperature, density, pressure, magnetic
field and gravitational field. Typically, they have a radius on the order of 10 km,
a mass between 1.44 and 3.2 solar masses and a core density up to 10
12 kg/cm
3 .
The pulsars belong to the neutron stars with very rapid rotation and have extremely
stable periodicity. Especially, the periodic change rates of millisecond pulsars can
get to 10
–19
−10
–21 s/s, and hereby the millisecond pulsars are known as the most
stable clocks in nature. The pulsars are not only very significant for the studies
on astronomy, astrophysics and cosmology but also have the potential application
values for high-energy physics, time–frequency science and space science. The X-ray
signals radiated from the pulsars can provide high-precision autonomous navigation
information for spacecrafts. So, the pulsars are able to become the lighthouses of
space flights for human beings.
1.1 Theoretically Predicted Neutron Stars
As everyone knows, the end of stellar evolution will produce finally compact stars,
including white dwarfs, neutron stars and black holes. The white dwarf was discovered empirically when scientists could not understand what are the celestial bodies
or the radiating sources, the neutron star was accidentally found on the basis of theoretical prediction, and the black hole has been investigating theoretically up to now.
© National Defense Industry Press and Springer Nature Singapore Pte Ltd. 2021
P. Shuai, Understanding Pulsars and Space Navigations, Navigation: Science
and Technology 11, https://doi.org/10.1007/978-981-16-1067-7_1
1