Neutron Star

Question 1

Prediction and Discovery

Answer 1

Walter Baade and Fritz Zwicky predicted the existence of neutron stars in 1934.
Jocelyn Bell first discovered a Pulsar (a type of neutron star) in 1967.

Question 2

Nuclear fusion

Answer 2

Stars exist because of the balance between the mass of trillions of tons of hot plasma and gravity.
Gravity squeezes the material together with so much force that nuclear fusion occurs: hydrogen fuses into helium

Question 3

Death of a Medium Star

Answer 3

Medium stars, like our Sun, go through a giant phase, where they burn helium into carbon and oxygen before they eventually turn into white dwarfs
Medium Star–> Subgiant–>Red Giant–>White Dwarf

Question 4

Death of a Massive Star

Answer 4

When the helium fuel is exhausted the balance between pressure and radiation tips and gravity wins which squeezes the star tighter than before
The core burns hotter and faster while the outer layers swell, fusing heavier and heavier elements

Question 5

Core Collapse

Answer 5

The iron in the core is ”nuclear ash”, meaning, it has no energy to give and cannot be fused.
The pressure is so great electrons and protons fuse into neutrons which then get squeezed together as an atomic nuclei in an event called electron capture.
An iron ball the size of Earth is squeezed into a ball of pure nuclear matter the size of a city.

Question 6

Supernova

Answer 6

Gravity pulls the outer layers in at 25% the speed of light, the implosion bounces off the iron core which produces a shockwave outwards and catapults the rest of the material into space

Question 7

Neutron Star

Answer 7

What remains after the supernova is a neutron star. It has a 1-2 solar masses but is compressed to an object 25 km (15.5 miles) wide

Question 8

Structure

Answer 8

Atmosphere: Carbon atmosphere

Crust–> Outermost layers: Extremely hard and made of iron leftover from the supernova that is squeezed together in a crystal lattice with a sea of electrons flowing through them

Core: Not sure of the properties of matter when they are squeezed this hard

Question 9

Nuclear Pasta in the Crust

Answer 9

Gnocchi phase
Spaghetti phase
Lasagna phase

Question 10

Pulsar

Answer 10

Pulsars are rotating neutron stars observed to have pulses of radiation at very regular intervals that typically range from milliseconds to seconds

Question 11

Magnetar

Answer 11

In a typical neutron star the magnetic field is trillions of times that of Earth’s but in a magnetar the magnetic field is another 1,000 times stronger