1. By
Carla Bridges

2.  5.3.2 Observe and describe that stars are like the sun,
some being smaller some being larger, but they are so
far away that they look like points of light.
 5.3.3 Observe the stars and identify stars that are
unusually bright and those that have unusual colors,
such as reddish or bluish.
 Language Arts:
 5.2.1 Structural Features of Informational and
Technical Materials: Use the features of informational
texts, such as formats, graphics, diagrams,
illustrations, charts, maps, and organization, to find
information and support understanding. (Core
Standard)

3.  Click on this icon to go to Table of contents.
 Click
on this icon for picture of star on that
page.
 Click on this icon for narration.
 Click
high-lighted words for more
information.

4.  Star Formations
 Types of Stars
 Colors of Stars
 Temperature of Stars
 Life Cycle of Stars
 Vocabulary
 Resources

5.  Stars form from collapsing clouds of gas
and dust.
 As the cloud collapses, its density and
temperature increase.
 The temperature and density are highest
at the center of the cloud, where a new
star will eventually form.
 A protostar is the beginning stage of a star.
 Stars will either form into low mass stars or
high mass stars.

6. Birth of a Star
 The type of star formed depends on what
type of fusion happens.
 Click here for more information on high-mass
and low-mass stars.
 High-mass and low mass stars have different
life cycles.
 High-mass stars evolve quicker and go
supernovae.
 Low mass stars turn into white dwarfs.

7. A protostar is what you have before a star
forms. A protostar is a collection of gas that
has collapsed down from a giant molecular
cloud. The protostar phase of stellar
evolution lasts about 100,000 years. Over
time, gravity and pressure increase, forcing
the protostar to collapse down. All of the
energy release by the protostar comes only
from the heating caused by the gravitational
energy – nuclear fusion reactions haven't
started

8.  A T Tauri star is a stage in a star's formation and
evolution right before it becomes a main
sequence star. This phase occurs at the end of
the protostar phase, when the gravitational
pressure holding the star together is the source
of all its energy. T Tauri stars don't have enough
pressure and temperature at their cores to
generate nuclear fusion, but they do resemble
main sequence stars; they're about the same
temperature but brighter because they're a
larger. T Tauri stars can have large areas of
sunspot coverage, and have intense X-ray flares
and extremely powerful stellar winds. Stars will
remain in the T Tauri stage for about 100 million
years.

9. A star in the main sequence is in a state of
hydrostatic equilibrium. Gravity is pulling the
star inward, and the light pressure from all
the fusion reactions in the star are pushing
outward. The inward and outward forces
balance one another out, and the star
maintains a spherical shape. Stars in the
main sequence will have a size that depends
on their mass, which defines the amount of
gravity pulling them inward

10.  When a star has consumed its stock of hydrogen
in its core, fusion stops and the star no longer
generates an outward pressure to counteract the
inward pressure pulling it together. A shell of
hydrogen around the core ignites continuing the
life of the star, but causes it to increase in size
dramatically. The aging star has become a red
giant star, and can be 100 times larger than it
was in its main sequence phase. When this
hydrogen fuel is used up, further shells of helium
and even heavier elements can be consumed in
fusion reactions. The red giant phase of a star's
life will only last a few hundred million years
before it runs out of fuel completely and
becomes a white dwarf.

11.  When a star has completely run out of hydrogen
fuel in its core and it lacks the mass to force
higher elements into fusion reaction, it becomes
a white dwarf star. The outward light pressure
from the fusion reaction stops and the star
collapses inward under its own gravity. A white
dwarf shines because it was a hot star once, but
there's no fusion reactions happening any more.
A white dwarf will just cool down until it
because the background temperature of the
Universe. This process will take hundreds of
billions of years, so no white dwarfs have
actually cooled down that far yet.

12.  Red dwarf stars are the most common kind of
stars in the Universe. These are main
sequence stars but they have such low mass
that they're much cooler than stars like our
Sun. They have another advantage. Red
dwarf stars are able to keep the hydrogen
fuel mixing into their core, and so they can
conserve their fuel for much longer than
other stars. Astronomers estimate that some
red dwarf stars will burn for up to 10 trillion
years. The smallest red dwarfs are 0.075
times the mass of the Sun, and they can have
a mass of up to half of the Sun.

13.  Ifa star has between 1.35 and 2.1 times the
mass of the Sun, it doesn't form a white
dwarf when it dies. Instead, the star dies in a
catastrophic supernova explosion, and the
remaining core becomes a neutron star. As its
name implies, a neutron star is an exotic
type of star that is composed entirely of
neutrons. This is because the intense gravity
of the neutron star crushes protons and
electrons together to form neutrons. If stars
are even more massive, they will become
black holes instead of neutron stars after the
supernova goes

14.  The largest stars in the UniverseThe largest
stars in the Universe are supergiant stars.
These are monsters with dozens of times the
mass of the Sun. Unlike a relatively stable
star like the Sun, supergiants are consuming
hydrogen fuel at an enormous rate and will
consume all the fuel in their cores within
just a few million years. Supergiant stars live
fast and die young, detonating as
supernovae; completely disintegrating
themselves in the process are supergiant
stars.

15.  Greenish
 Blue
 White
 Whitish-yellow
 Yellow
 Yellowish-orange
 Orange
 Orange-red
 Red

16. Color Temperature
Blue Over ~ 25,000 K
White ~7,000 K
Yellow ~6,000 K
Orange ~5,000 K
Red ~Under 3,500 K

18.  Celestial object- natural object in the sky
 Solar mass- the unit, equivalent to the mass
of the sun, in which the masses of stars and
other celestial objects are given
 Solar unit- the unit, equivalent to the length
between the Earth and the Sun: 93 million
miles or 150 million kilometers
 Stellar evolution- the lives of stars
 Stellar wind- flow of neutral or charged gas
ejected from the upper atmosphere of a star.

19.  X-ray flares- happens when energy stored in
twisted magnetic fields (usually above sunspots)
is suddenly released. Flares produce a burst of
radiation across the electromagnetic spectrum,
from radio waves to x-rays and gamma-rays.
 Sunspots- Any of the relatively cool dark spots
appearing periodically in groups on the surface
of the sun that are associated with strong
magnetic fields.
 Planetary nebula-forms when a star can no
longer support itself by fusion reactions in its
center. The gravity from the material in the
outer part of the star takes its inevitable toll on
the structure of the star, and forces the inner
parts to condense and heat up

20.  http://www.innvista.com/science/astronomy
/types.htm
 http://www.universetoday.com/guide-to-
space/stars/types-of-stars/
 http://docs.kde.org/development/en/kdeed
u/kstars/ai-colorandtemp.html
 http://outreach.atnf.csiro.au/education/sen
ior/astrophysics/photometry_colour.html
 http://www.ipac.caltech.edu/Outreach/Edu
/sform.html

21.  http://images.google.com/images?q=types+o
f+stars&rls=com.microsoft:*:IE-
SearchBox&oe=UTF-
8&sourceid=ie7&rlz=1I7GGLL_en&um=1&ie=U
TF-
8&ei=dqzfSrp_jZowqZjEwwg&sa=X&oi=image
_result_group&ct=title&resnum=4&ved=0CCM
QsAQwAw
 http://dictionary.reference.com/