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Neutron Stars
nucleus: =1.2*10^14 gm cm^-3 R=1.5*10^-13 cm m=1.7*10-24 gm mass: 1.4 Msun=2.8*10^33 gm Therefore, volume: 2.3*10^19 cm^3, and radius=1.8*10^6cm = 18 km
Structure Pressure is immense
Pulsars Discovery in 1968 Unobservable, as they have no atmosphere In hindsight, they should have realized this was false, neutron stars have large B field. Therefore 10^10 Bsun ~10^12 gauss Will be rotating rapidly Electron at surface if 10 rotations per second v=10 * 2pR cm s^-1 = 1.2*10^8 cm s^-1=0.004c E + 0.0004 * 10^12 = 0 E= 4* 10^9 e=4.8 * 10^-12 F=eE=1 dyne Fe >> Fg therefore rips particles from surface This magnetosphere emits radio radiation from charged particles getting thrown around We dont see all pulsars because we miss their beams Crab Pulsar Shows Slows down because radiation supplies energy Glitches speed up suddenly "star quakes" Neutron stars X-ray mass transfer
Binary Pulsars companion collapsed also Laboratory for general relativity gravitational radiation will cause system to spiral in Recent studies first proof of gravitiational waves.
Mass Tansfer Binaries What happens when stars get close together and one is a collapsed object? A lot! From Keplers law: P ~ R3/2 When stars get close enough to touch an orbit takes 3 hours to a few days Formation of an accretion disk Two things run the mass transfer: giant radius and mass loss, spiral together.
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