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Astronomy Notes
1. Astronomy is:
Science that deals with
celestial objects, space,
and the physical
universe
2. The Universe consists of:
All of space and the matter it
contains
3. Galaxies are:
Large grouping of stars in space
4. Describe and draw 3 categories of
Galaxies :
1.Spiral (disc) shaped galaxies they have
a bulge in the center and distinct spiral
shaped arms.
2. Elliptical galaxies – have a
spherical or elongated shape
3. Irregular galaxies – have no
distinct shape
5. The earth is located in
which category of galaxy?
Spiral/Disc shaped
What is the name of our galaxy?
The Milky Way galaxy
6.Stars are:
Huge objects in space that give off
light and heat
They are born in a large cloud of gas and dust
Called the Nebula
AKA Hollywood of the Solar system
7. There are many stars in the Milky
way Galaxy. Our sun is a medium
sized star. It is located in an outer arm
of the galaxy and is the source of all
Life on earth. The sun’s mass makes
up over 99% of the mass of the entire
solar system
8. Light and heat from stars come from
nuclear reactions within the star. The main
gasses that make up stars are Hydrogen and
helium. Young stars are rich in Hydrogen,
while older stars are rich in Helium.
9. The Hertzsprung-Russel Diagram ( H-R
diagram) shows:
The relationship between a stars temperature
and its Luminosity.
10. The Astronomers use the H-R diagram to:
Classify stars according to their color, temperature,
luminosity, spectra type, and evolutionary stage.
H-R diagram
H-R diagram
H-R diagram
11. Stars are measured by their Temperature which
is shown on the X axis of the H-R Diagram and
their brightness or luminosity which is measured
on the Y axis of the H-R diagram.
Most stars spend their lifespan on the Main
Sequence of the H-R diagram.
12. The amount of energy produced by a star
determines its surface temperature and color.
Hot stars are : blue or white
The coolest stars are : orange or red
Life Cycle of a Star
13. Moon’s are:
Natural satellites of a planet
14. Comets are:
Bodies of ice and rock and dust that orbit
the sun
15. Asteroids are :
A small rocky body that
revolves around the sun
16. Meteoroid's are (in space) :
Rocky bodies (smaller than an asteroid) that
orbit the sun
Meteors are (in the atmosphere):
A meteoroid that burns and vaporizes
“shooting stars”
Meteorites are (on the ground) :
A meteor that survives the atmosphere and
lands on the earth. ( 90% Iron)
17. A Light year is a unit of length ( not time) in
Astronomy that is equal to the Distance light travels
in one year in a vacuum. ( approximately 5.88
trillion miles or 9.46 trillion Kilometers.
It takes one year for light to travel one light
year
It takes 8.3 minutes for light to travel from the sun.
It is 8.3 light minutes away.
18. Wavelengths travel through
th4e earth’s atmosphere with
varying frequencies.
Objects in space that are in redshift
are moving away from earth
Objects in space that are in blueshift
are moving toward earth(blue to
you)
Draw a picture of the Milky way galaxy.
Place a dot in one of the outer arms to
represent our solar system