Stars, Galaxies and Nebulae
Another state of Matter
• Solids, Liquids and
Gasses
• Plasma—like a gas,
except can be charged
electrically
• In this plasma lamp,
electricity and magnet
form structures
Some common Plasmas
• Fire
• Lightning
• The Sun and
other stars
What is a star?
• A Luminous Ball of
Plasma held
together by gravity
Helium
• Fueled by Nuclear
Fusion
A star begins
• With a
collapsing
cloud of
material
• Mostly made
of Hydrogen,
the lightest,
simplest
element
•
a photograph of the center of the Swan
Nebula, or M17, a hotbed of newly born
stars wrapped in colorful blankets of glowing
gas and cradled in an enormous cold, dark
hydrogen cloud.
One Nebula, two Nebulae
• Clouds of dust and
gas (especially
hydrogen) where
stars form
• The Horsehead
Nebula
A Gallery of Nebulae
• The
Bubble
Nebula
• The Eagle
Nebula
• HH-666
• Also
known as
“the axis of
evil in the
Carina
Nebula”
• Rossette
Nebula
• Part of the
Eagle
Nebula
• Triangulum
Emission
Garren
Nebula
• Cat’s Eye
Nebula
• Red
rectangle
nebula
How do they take these pictures?
• The Hubble
Telescope
• Launched
in 1990
• Will stop
working this
year
Webb telescope
• Will be
launched
in 2013
• Will be
beyond
the moon
Galaxies
• Huge
groups of
stars,
• Star
clusters
• Interstellar
clouds
Types of Galaxies
• Elliptical
• Spiral
• A Barred
Spiral
Galaxy
Milky Way
• Our Home
Galaxy!
• A Barred
Spiral Galaxy
• Ring
Galaxy
• Starburst
Galaxies
• Stars form at
a fast rate
How many galaxies?
• More than 170
billion
• 170,000,000,000
• More being
discovered all the
time!
How many Stars in a Galaxy?
• As few as 10 million
(10,000,000)
• As many as 1 trillion
(1,000,000,000,000)
Dark Matter
• We can’t see it
• But it has gravity– a lot!
• Makes up 90% of
galaxies
• Something scientists are
trying to find out about
right now
?
Black Holes
• A place from
which nothing can
escape
• Not even light!
• Very compact
mass in a
deformation of
spacetime
Supermassive Black Hole
• What it sounds like
• At the center of
most, if not all,
galaxies
• Here, an artist has
imagined a
supermassive
black hole tearing
a star apart
Supernova
• A star
explosion
• Burns all its
material in a
few weeks or
months
Red Giants
• Towards the end
of a star’s life
• Expands to 9
times it size
• Starts to fuse
carbon, neon,
silicon and
oxygen
• This star is
Betelgeuse
Collapse
• Will eventually
collapse into a
“planetary
nebula”
• Remnants may
be recycled into
new stars
Quiz-time!
• What element is being fused in the sun
and other stars to make energy and
helium?
• Hydrogen
• What do we call gas that can be
electrically charged?
• Plasma
• Some examples?
• Fire, lightning, stars
• What do we call a
region of clouds of
gas where stars
form?
• a Nebula
• The plural?
• Nebulae
• What is the name
of this nebula?
• The Horsehead
Nebula
• What will not let anything escape, not even
light?
• A Black Hole
• What is a star explosion called?
• A Supernova
The End