PHYS 1010 Chapter Notes - Chapter 13: Special Relativity, Globular Cluster, Solar Mass

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coffeebuffalo475

23 Apr 2016

School

University of Windsor

Department

Physics

Course

PHYS 1010

Professor

Mark Lubrick

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Chapter 13 - neutron stars and black holes. After a type i supernova, little or nothing remains of the original star. After a type ii supernova, part of the core may survive. It is very dense as dense as an atomic nucleus- and is called a neutron star. Neutron stars although they have 1-3 solar masses, are so dense that they are very small. This image shown a 1-solar-mass neutron star, about 10km in diameter compared to manhatten. Other important properties of neutron stars (beyond mass and size) Rotation as the parent star collapses, the neutron core spins very rapidly, conserving angular momentum. As the giant object collapses it ends to spin faster! Magnetic field again as a result of the collapse, the neutron star"s magnetic field becomes enormously strong. The first pulsar was discovered in 1967. It emitted extraordinarily regular pulses; nothing like it had ever been seen before.

Related Questions

Most stars maintain an equilibrium size by balancing two forces - an inward gravitational force and an outward force resulting from the star's nuclear reactions. When the star's fuel is spent, there is no counterbalance to the gravitational force. Whatever material is remaining collapses in on itself. Stars about the same size as the sun become white dwarfs, which glow from leftover heat. Stars that have about three times the mass of the Sun compact into neutron stars. And a star with a mass greater than three times the Sun's mass collapses into a single point, called a black hole. In most cases, protons and electrons are fused together to form neutrons - this is the reason for the name neutron star. Neutron stars rotate very fast because of the conservation of angular momentum. Imagine a star of mass 7.29·1030 kg and radius 9.05·108 m that rotates once in 26.0 days. Suppose this star undergoes gravitational collapse to form a neutron star of radius 12.3 km. Determine its rotation speed.

Most stars maintain an equilibrium size by balancing two forces - an inward gravitational force and an outward force resulting from the star's nuclear reactions. When the star's fuel is spent, there is no counterbalance to the gravitational force. Whatever material is remaining collapses in on itself. Stars about the same size as the sun become white dwarfs, which glow from leftover heat. Stars that have about three times the mass of the Sun compact into neutron stars. And a star with a mass greater than three times the Sun's mass collapses into a single point, called a black hole. In most cases, protons and electrons are fused together to form neutrons - this is the reason for the name neutron star. Neutron stars rotate very fast because of the conservation of angular momentum. Imagine a star of mass 5.57·1030 kg and radius 8.85·108 m that rotates once in 26.0 days. Suppose this star undergoes gravitational collapse to form a neutron star of radius 14.9 km. Determine its rotation speed.

During most of its lifetime, a star maintains anequilibriumsize in which the inward force of gravity on each atomis balancedby an outward pressure force due to the heat of thenuclearreactions in the core. But after all the hydrogen "fuel"isconsumed by nuclear fusion, the pressure force drops and thestarundergoes a gravitational collapse until it becomesaneutron star. In a neutron star, the electrons andprotonsof the atoms are squeezed together by gravity until theyfuse intoneutrons. Neutron stars spin very rapidly and emit intensepulsesof radio and light waves, one pulse per rotation. These"pulsingstars" were discovered in the 1960s and arecalledpulsars.

1.A star with the mass (M= 2.0 x 10^30) and size (R= 3.5x10^8) of our sun rotates once every 35.0 days. Afterundergoinggravitational collapse, the star forms a pulsar that isobserved byastronomers to emit radio pulses every 0.200s. Bytreating theneutron star as a solid sphere, deduce itsradius.

2.What is the speed of a point on the equator of theneutronstar? Your answer will be somewhat too large because a starcannotbe accurately modeled as a solid sphere.

PHYS 1010 Chapter Notes - Chapter 13: Special Relativity, Globular Cluster, Solar Mass

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