Transcript The Milky Way and other Galaxies

Galaxies
Galaxy
A
large assembly of
stars and nebulae
Group of Galaxies
The Milky Way
Our
galaxy
Flat disk with spiral
arms
More about galaxies
There are 3 major types of galaxies
 Spiral
 Elliptical
 Irregular

Spiral galaxies.


Disk
shaped
with a
central
bulge.
The
center is
black
Hole
Elliptical galaxies
Elliptical
or round
shape
 No disk
 Stars
but no
gas

Irregular galaxies

Irregular shape, and does not swirl.
Inside the Galaxies
Nebulas
(space gas clouds found in spiral
galaxies)
 Globular Clusters
(groups of older stars at the edge of
galaxies)
 Open Clusters
(smaller groups of clusters younger stars)

Milky Way

Spiral

Contains single stars, double stars, star
systems, dust and gases

Shaped like a disk with a bulge in the center

The bulge is very dense
The Milky Way Galaxy contains dust and
gas.
Our Solar System is located in Orion’s Arm
of the Milky Way Galaxy.
More Facts about the Milky Way…



Held together by gravity
Can be seen on a very clear night
Got its name from the hazy/milky appearance
Our Solar System
Is located in the Milky Way Galaxy
 Is a single star system (Sun)

Quick Facts about the Sun
A medium sized star
 Located near the edge of the Milky Way—
did you see it in the previous slide?

Supernova

A _____________ is basically the death of
a large star by explosion.
An exploding star is known as a supernova.
Quasars
Small,
powerful
source of energy
thought to be cores
of distant spiral
galaxies
They
emit radio
waves and bright light
Black Holes
A
_______ is a giant star
or group of stars that
has/have collapsed
because of their
enormous gravity.
Where did its name come from?
It
is called a black
hole because not even
light can escape!
.
A pattern or
group of stars in
the sky is called
a constellation.
Different Constellations Star Patterns
The Big Dipper
Why do constellations change from
season to season?

Because the Earth orbits the sun!

Most constellations appear in many
different positions in the sky as the Earth
revolves around the sun.
Constellations

Earth rotates on its axis, this makes most
constellations appear to rise in the east and
set in the west during the night.

There is a group of stars that appear in the
sky all night long and all year long. It seems
that these stars do not rise and set, but
circle the Earth’s north pole each night.
These stars are called circumpolar.