The Universe Life Death of a star Video

The Universe – Life & Death of a star Video © 2010 D Taylor

1. • What are the “Pillars of Creation” made of? –Dust & H

2. • What is the most important force in astro? –Gravity

3. • What is the early stage of a star called once the dust begins to clump? –Nebula

4. • In what stage does a star spend most of its life? –Main Sequence

Low Mass Evolution

Summary of Post Main-Sequence Evolution of Stars Supernova Fusion proceeds; formation of Fe core. M > 8 Msun Evolution of 4 - 8 Msun stars is still uncertain. Mass loss in stellar winds may reduce them all to < 4 Msun stars. Fusion stops at formation of C, O core. M < 4 Msun M < 0. 4 Msun Red dwarfs: He burning never ignites

Stellar evolution made simple Bless You! 0. 077 ~8 Mo ~8 ~20 Mo Bang! HECKUVA BANG! ~20 ~100 Mo Stars like the Sun go gentle into that good night More massive stars rage, rage against the dying of the light

High Mass Evolution

5. • What characteristic indicates how hot a sun is? –Color

6. • Small cool red stars are called…? –Red dwarf

7. • Blue stars are how much bigger than the sun? –~ 20 x

8. • Which stars live longest? Small or Large mass ones? –Small mass stars

9. • What will happen to our sun when all the H is burned? –It’ll burn a little He then die… OH NOZE!!!

Introduction • Main Sequence – Graph of stars lives

10. • What is the phase of a star where it just cools down and fades away? –White dwarf (us)

11. • Why do most stars not die in the time we expect? –They begin to fuse heavier elements and keep on truckin’

Introduction

12. • What is the result of the collapse of the iron core of a massive star? –It explodes violently in a supernova

Introduction

13. • Where did all the atoms in your body originate? –Stars and their explosive deaths

14. • How big are neutron stars? –~10 mi across (size of Manhattan…)

Properties of Neutron Stars Typical size: R ~ 10 km Mass: M ~ 1. 4 – 3 Msun Density: r ~ 1014 g/cm 3 Piece of neutron star matter of the size of a sugar cube has a mass of ~ 100 million tons!!!

15. • What would happen to the sun if a white dwarf collided with it? –Sun would distort (eggshaped) then explode

16. • What did the show compare with a globular cluster of stars? –A demolition derby

17. • What do they call the young blue stars found in clusters? –Blue stragglers

18. • Where does Joshua Barnes (the hippy) think they came from? –Collisions between the older dimmer main sequence stars already there

19. • At what stage of a star’s life are black holes, white dwarfs, …? –End stages (death)

20. • What is a brown dwarf? –Failed star

Brown Dwarfs Hard to find because they are very faint and cool; emit mostly in the infrared. Many have been detected in star forming regions like the Orion Nebula.

Introduction 1987 1984

Introduction 1987 – Close up

Introduction

Introduction

Introduction

Introduction