Dying StarsPart 1

Neutron Stars

• Supernovas make some pretty “remanants” also.

• The Crab Nebula was seen in 1054 CE

• It has a Neutron Star in the center – in addition to blinking on and off – it also gives a radio sound. (Pulsar)

• Pulsars– When a large mass star ends its life in an

explosion – a supernova – the core of the star goes on to form one of two things – a Black Hole (if the star’s mass was high) or a Neutron Star – if the mass was a bit lower.

– The Neutron Star (and the Black Hole) will be spinning. IF the orientation of the spin axis, and magnetic fields – line up correctly – we can hear them in the Radio – they are Pulsars.

• The first Pulsar was discovered by Jocelyn Bell.

• She was a Student whenshe found thePulsar, so herprofessor gotmost of the Credit. Most people now giveher the credit.

• Sounds of Pulsars – Rapidly Spinning Neutron Stars

Crab – Supernova in 1054 AD - ~ 30 rotations/sec

PSR J0437-4715 an old pulsar ~ 174 rotations/sec

PSR B0329 + 54 period=.714519 sec. 1.40 rotations/sec

PSR B1937+21 Fastest Known – Period=.00155780644887275 sec ~642 rotations/sec the surface of the star is going about 1/7 the speed of light

Vela – 10,000 years old – 89 millisecond – 11 rotations/sec