Neutron StarsNeutron Stars

By: Matthew BuzaBy: Matthew Buza

Star PowerStar Power Importance of Stars and their role Importance of Stars and their role

in the universe.in the universe. Overview of all stars, and basic Overview of all stars, and basic

characteristics.characteristics. Stellar Evolution: Start Stellar Evolution: Start finish finish Path to a Neutron Star.Path to a Neutron Star. Further work being done.Further work being done.

Stars?Stars? Star Characteristics are given by:Star Characteristics are given by:

Luminosity Luminosity Ave. MassAve. Mass Ave. DiameterAve. Diameter

Which all determines Main Which all determines Main Sequence Time.Sequence Time.

Ex. The sun is a Ex. The sun is a G2(spectoral class) and G2(spectoral class) and has a main sequence time has a main sequence time of 12 billion years.of 12 billion years.

Stellar EvolutionStellar Evolution Laws same here as they are on other Laws same here as they are on other

planets, stars, universe.planets, stars, universe. Gravity is the same thing that keeps Gravity is the same thing that keeps

you on the ground, and the earth going you on the ground, and the earth going around the sun.around the sun.

We are chemically the same material We are chemically the same material as planets, stars.as planets, stars.

Important to understand the world Important to understand the world around us.around us.

Exploring here on earth workings of Exploring here on earth workings of stars we understand better the cosmos stars we understand better the cosmos and ourselves. and ourselves.

Understand the basic principles that Understand the basic principles that govern our world and us.govern our world and us.

Nothing Wrong With Second BestNothing Wrong With Second Best

Not just the stars we should study, but the by products of them.Not just the stars we should study, but the by products of them. Basically, we are looking at the competition of Gravity vs. everything Basically, we are looking at the competition of Gravity vs. everything

else( kinetic effects, nuclear forces, degeneracy's, electro-magnetic)else( kinetic effects, nuclear forces, degeneracy's, electro-magnetic) Normal stars are fighting with Hydrodynamic pressure, and radiation Normal stars are fighting with Hydrodynamic pressure, and radiation

pressure.pressure. But in by-products we see both electron and neutron degeneracy’s, But in by-products we see both electron and neutron degeneracy’s,

along with neutrino pressures. Where density is the dominating along with neutrino pressures. Where density is the dominating factor.factor.

Mainly, White Dwarfs, Neutron Stars, and Black holes.Mainly, White Dwarfs, Neutron Stars, and Black holes.

The Touch of GodThe Touch of God SupernovaSupernova

Star begins to fuse iron, which Star begins to fuse iron, which eats up energy.eats up energy.

Causes the star to contract, Causes the star to contract, gravity taking overgravity taking over

Varying densities causes Varying densities causes pressure build up, and then the pressure build up, and then the ‘bounce’ (degenerate core), the ‘bounce’ (degenerate core), the star violently ejects large amounts star violently ejects large amounts of the star into space.of the star into space.

Small Stellar objects are left Small Stellar objects are left behind, depending on the core behind, depending on the core that is left (mass).that is left (mass).

This dictates the finally product, This dictates the finally product, governed by the Chandrasekar governed by the Chandrasekar limit (1.44 sol) , which is the limit (1.44 sol) , which is the maximum mass of a white dwarf maximum mass of a white dwarf star.star.

Neutron Stars are generally 1.4-3 Neutron Stars are generally 1.4-3 solar masses.solar masses.

Neutron StarsNeutron Stars

From massive White From massive White Dwarf stars to Neutron Dwarf stars to Neutron starsstars

Cooling of the WDS, forms a Fe Cooling of the WDS, forms a Fe lattice, with intermittent heavier lattice, with intermittent heavier elements spread throughout.elements spread throughout.

Supported by Electron Supported by Electron degeneracy, has a completely degeneracy, has a completely free degenerate electron gasfree degenerate electron gas

If Fermi energy exceeds the If Fermi energy exceeds the Neutron-Proton mass difference, Neutron-Proton mass difference, new exothermic reaction occurs, new exothermic reaction occurs, Reverse Beta-DecayReverse Beta-Decay

e + p e + p n + v n + vee

Supported by Neutron DegeneracySupported by Neutron Degeneracy..

Neutron StarsNeutron Stars From White Dwarf star to Neutron From White Dwarf star to Neutron

starstar Density from 1000 tons per cubic Density from 1000 tons per cubic

inch to 10 billion tons per cubic inch to 10 billion tons per cubic inch.inch.

From 10,000 miles in diameter to From 10,000 miles in diameter to about 10 miles.about 10 miles.

What is being worked on?What is being worked on? ‘‘Pasta’ simulations here at FSU.Pasta’ simulations here at FSU.

Studying multiple Studying multiple densities, running densities, running simulations and looking for simulations and looking for ‘clumping’ of the protons. ‘clumping’ of the protons.

Exploring these Exploring these characteristics could help characteristics could help to describe many of the to describe many of the characteristics of the characteristics of the neutron starsneutron stars

Surface features, Surface features, starquakes, spinning up or starquakes, spinning up or down of the star (pulsars). down of the star (pulsars).

We hope that this could We hope that this could open up some explanation open up some explanation for why things happen.for why things happen.