1. 1 Death of a Large Mass Star
The Death of a Large Mass Star
1 Death of a Large Mass Star
Large stars begin in a similar way to a small mass star.
Nebula to Protostar
Young Star to Main Sequence
However, Large mass stars have a much more interesting end to their lives.

2. The Death of a Large Mass Star
2 The Baby’s a Whopper!
The Eagle Nebula is an example of a very large nursery for stars.
There is a lot of hydrogen gas and dust in this cloud to form stars with very large masses. (Masses which are twice as large as our Sun and more!).
The evolution of a star depends upon how much hydrogen gas it manages to collect at the start.

3. The Death of a Large Mass Star
3 Red Supergiants
You can easily find a red supergiant in the constellation of Orion.
Red supergiants can be far larger than the orbit of Jupiter.
Jupiter
Red Supergiant

4. The Death of a Large Mass Star
Supernova
The Death of a Large Mass Star
4 Red Supergiant to
A Red Supergiant quickly uses up its supply of fuel and its core will collapse suddenly.
The core compresses and then explodes through the outer layers of the star which are then flung out into space.
The explosion is called a supernova.
This material could form another nebula from which other stars could be born.

5. The Death of a Large Mass Star
5 Neutron Stars
The Supernova leaves behind a super compressed core called a Neutron star.
A typical neutron star has a mass between 1.35 and 2.1 solar masses, with a corresponding radius between 10 and 20 km.
20km
The density of these stars are about 10x1013 g/cm3.

6. The Death of a Large Mass Star
6 Pulsars
In the Crab Nebula is a special type of neutron star called a Pulsar.
A Pulsar emits EM Radiation a bit like a lighthouse.
Crab Pulsar ON
OFF
X-Ray Picture
This is the youngest known pulsar and lies at the centre of the Crab Nebula. the supernova explosion was witnessed by Europeans and Chinese in the year 1054 A.D. as a day-time light in the sky.
The pulsar rotates about
30 times a second.

7. The Death of a Large Mass Star
Black Holes
7 Black Holes
If a really large star explodes then the collapsing core will not stop at just forming a neutron star.
It will continue collapsing until it forms the densest object in the universe which is called a Black Hole.
Swirling gas can be detected falling into this object.
In fact the gravity field is so strong that even light cannot escape its attraction. This is why it is called black.
Black Hole can be detected by the EM radiation emitted by the swirling gas as it falls into the hole or by looking at a star which is locked into orbit around the hole.

8. The Death of a Large Mass Star
8 A Hole in What?
How can a star collapse and form a hole? What does it make a hole in?
Imagine the 3-Dimensions of space as a flat stretchy piece of rubber. ?
Mass causes space to warp and change shape.
The denser the star the deeper the depression (gravitational well)

9. 8 Super Massive Black Holes
The Death of a Large Mass Star
8 Super Massive Black Holes
Blacks hole can form in other ways such as two heavy stars combining together to warp space.
Astronomers now think that at the centre of every galaxy lurks a super massive black hole which keeps all the other stars in orbit.