Transcript Life-DeathofaStar-Videox

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
Bang!
~8
~20
~20 Mo
HECKUVA
BANG!
~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/cm3
 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