3. TEKS 8.8A describe components of the
universe including stars, nebulae and
galaxies, and use models such as the
Herztsprung-Russell diagram for
classification
TEKS 8.8B recognize that the Sun is a
medium-sized star near the edge of a
disc-shaped galaxy of stars and that
the Sun is many thousands of times
closer to the Earth than any other star
4. We live in a galaxy
called the Milky Way.
A galaxy is a system
of stars, planets gas,
dust and dark matter.
5.
6. Within galaxies are star
forming regions called
nebula. A nebula is a
cloud of dust, hydrogen
and helium gases.
7. It is in these clouds
of gas and dust that
stars sometimes
form.
8. A star is a
large ball of
gases that
generates
its own
energy
through
nuclear
fusion.
9. Fusion is a
process in
which
hydrogen
and helium
fuse to form
heavier
elements.
13. Depending on the mass
of the star, its lifetime
may be a few million
years to trillions of
years. Lower massed
stars can generate
energy for billions of
years.
14. Stars that are very
massive generate
energy for only a few
million years.