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Name ________________________________________ Date _____________________ Hr______________
STUDY GUIDE
DIRECTIONS: Complete the following study guide on a separate sheet of paper. THIS IS DUE THE
DAY OF THE TEST!!!
Star Magnitudes
Star
Absolute
Magnitude
Apparent
Magnitude
Canopus
-2.5
-0.72
Rigel
Kentaurus
+4.4
-0.27
Vega
+0.6
0.03
Capella
+0.4
+0.08
Archenar (in
Eridanus)
-1.3
+0.46
Betelgeuse
-7.2
+0.50
Hadar
-4.3
+0.61
Altair
+2.3
+0.77
Acrux)
-3.8
+0.79
Aldebaran
-0.2
+0.85
Deneb
-7.2
+1.25
Sirius
+1.4
-1.46
Procyon
2.8
+0.38
Questions: Use the chart to help you answer these:
1. What is the difference between absolute and
apparent magnitude?
Apparent magnitude – how bright a star looks from
earth
Absolute magnitude – how much light energy is
being released from an object
o The smaller, or more negative the number, the
more energy is being released.
Example  A star called Becrux has an absolute
magnitude of -3.92. Another star called Altair has
an absolute magnitude of 2.22. Becrux is giving off
more energy than Altair and is therefore a bigger
star.
The problem with absolute magnitude is that a
person cannot just look at a star and determine its
absolute magnitude. Just because a star looks
brighter from Earth doesn’t mean it is a bigger star
(a more negative absolute magnitude). If a star
looks brighter, it might just be closer!
2. Rank these stars in order from seemingly brightest
to dimmest
3. Rank these stars in order from actual brightest to
dimmest
4. Put the following astronomers in order and
compare the view that each had of the solar system
in detail, or list the major contributions to
astronomy.
-Copernicus - Created the first heliocentric model-----Aristotle - Believed in the geocentric model that
explained only the paths of the sun and moon
-Kepler - Created the heliocentric model that
abandoned the perfect circle
-Galileo - Was imprisoned till death for publishing his findings that supported Copernican theory
-Ptolemy - Responsible for the geocentric model involving up to 80 circles of the solar
-Einstein - Did not believe the information that his work supported and clung to the steady state
theory
-Hubble - Found definitive proof that the universe was expanding
-Brahe - An aristocrat that compiled extensive data and employed one of the astronomers on the list
-Newton - In simple terms, explained why the planets do not fly into space or fall into the sun
5. Explain the “fight” between the Big Bang Theory and the Steady State Theory.
Page 3 of notes
6. What does it mean that you can still “hear” the Big Bang and why was this important?
7. Describe the different types of the telescopes, and explain the function of each.
a) Infrared
c) X Ray
e) Optical
b) Gamma Rays
d) UV Rays
f) Radio
8. What is the STS and the MIR?
MIR is a space station
9. Explain what a constellation actually is.
A specific group of stars.
o Ancient people of many cultures connected groups of stars to form patterns, like huge dot-to-dot puzzles.
o These patterns are known as constellations.
10. List the types of radiation that we can see from Earth and the types that are blocked by earth’s
atmosphere.
Don’t need to know
11. What famous stars are often confused as constellations and what are they really? Big dipper and
Little dipper – they are actually asterisms - prominent patterns or groups of stars, typically having a
popular name but smaller than a constellation
12. Explain precession and what it means in the future - slow movement of the axis of a spinning body
around another axis due to a torque (such as gravitational influence) acting to change the direction of
the first axis – it means that we will have a new north star about 12,000 years from now
13. What are the 7 types of satellites and how is each used?
Scientific research - Gather data for scientific analysis. These satellites can be designed to perform
different types of missions.
Examples: Some gather information on earth, others orbit planets.
Communication - Connect distant places, make communication possible with remote areas.
Examples: Telephone, Television, Internet
Navigation - Use radio waves to locate positions
Examples:
GPS (Global Positioning System): 24 satellites spaced in orbits
so that a receiver anywhere on Earth, whether mobile or stationary, can
always receive signals from at least four satellites.
GLONASS (Global Orbiting Navigation satellite System):
satellite navigation system owned by Russia.
Meteorology - Record images of weather systems, show cloud
cover, and monitor hurricanes.
They also carry instruments to measure temperature, pressure and humidity used in weather
forecasting.
Earth resources - Help scientist study Earth’s surface. The satellite’s
instruments analyze light and other radiation reflected and emitted from surface features.
Military - Gather information about battlefields, take detailed
pictures, locate missing troops, and provide secure communications
14. How does parallax work with regard to distances of stars?
Parallax is the apparent shift in the position of an object when viewed from two different positions
The nearer an object is to the observer, the greater its parallax
15. Label all parts of the terrestrial globe. SEE NOTES AND QUIZ
16. Label all parts of the celestial sphere – Use appropriate diagram from notes and quiz
17. Explain Declination and Right Ascension.
These are coordinates. Just as any city on Earth can be located by its coordinates of longitude and
latitude, any sky object can be located on the celestial sphere by its coordinates of right ascension and
declination. Right ascension is similar to longitude and is measured in hours, minutes and seconds.
Declination is similar to latitude and is measured in degrees, arc minutes and arc seconds.
18. Use appropriate diagram:
A. Make a star at (1hr R.A, +60 )
B. Make a star at (22hr R.A., -20)
C. Make a star at (21hr R.A.,-60 )
D. Make a star at (2hr R.A., -35 )
E. Make a star at (18hr R.A, +15 )
19. What is an Epicycle? IGNORE THIS QUESTION
20. List the different types of space probes and the use of each.
Fly-By: Surveys its target as it flies past, often at a distance of several thousand kilometers.
Examples: MESSENGER is currently gathering information on Mars
2.
Orbiter: Travels to a planet or moon then moves into orbit around it.
Examples: Cassini-Huygens mission currently gathering information on Titan, a moon of Saturn
3.
Lander: Probes that land on the surface of a moon or planet. Usually start out as orbiters.
Examples: Phoenix Mars Lander
21. What is a parsec?
o We can only assign a value for absolute magnitude when we know the distance a star is from Earth.
The distances are in units called parsecs.
1 parsec=3.26 light years or 3.086 x 1013 kilometers
22. How many km is 3.216 parsecs? 9.92 x 10^13
23. How many km is 3.216 light years? 3.04 x 10^13
24. Use appropriate diagram: SEE NOTES AND QUIZ
A. Identify the area where stars can be seen all year in the northern hemisphere.
B. Identify the area where stars can never be seen in the northern hemisphere.
C. Identify the area showing where stars rise and set in the northern hemisphere.
D. Identify the Celestial Horizon.
E. Identify stars above and below the horizon.
25. Explain each of the local reference lines – Use appropriate diagram. PAGE 12 OF NOTES
26. Explain the importance of the following terms: Definitions in Notes
Ptolemaic Model - description of the universe with the Earth at the center
Heliocentric universe - the sun as the center of the universe
Ecliptic - the plane in which most of our solar system lies
Cosmology - the science of the origin and development of the universe.
South celestial pole – point on celestial sphere that corresponds with the terrestrial south pole
Geocentric universe - Earth as the center of the universe
Right ascension angle - The distance measured eastward along the celestial equator from the vernal
equinox. Right ascension is measured in hours, with 1 hour (h) equal to 15 degrees. Right ascension is
a projection of longitude on the terrestrial globe.
Declination - The angular distance above or below the celestial equator. Declination is measured in
degrees and is a projection of latitude on the terrestrial globe.
Celestial Meridian - The great circle passing through your zenith and the north and south points on
your horizon. Only half of the celestial meridian is above the horizon
Celestial sphere - Just know how to read/label the sphere and which areas we can see from MI (see
notes)
Zero hour circle – DON’T NEED TO KNOW
Celestial equator - The projection of the Earth’s equator out to the sky
Celestial Horizon - The circle on the celestial sphere 90 degrees from your zenith. You can see only
those stars that are above your horizon.
Zenith - The point on the celestial sphere directly over your head
North celestial pole
Astronomical Unit - 1 AU = 150 million km or 93 million miles (distance from center of the earth to
the center of the sun)
Latitude – horizontal lines
Longitude – vertical lines
Zodiac - A group of 13 constellations are known as the Zodiac and lie along the ecliptic
Vernal equinox - The longitudinal zero point similar to the prime meridian
Light year - Distances in space are often measured in light years. A light year is the distance that light
travels in one year.
Retrograde motion - The apparent “backward” motion of the planets Mars, Jupiter, and Saturn,
known as retrograde motion, refers to motion in the westward direction
Parsec - The distance at which a star must lie in order for its measured parallax to be exactly 1 arc
second.