Unit 1 Flashcards
Ursa Major
big dipper, No bright star
Ursa Minor
little dipper, Polaris
Casiopeia
the queen in chair, no bright star
Cepheus
The king in house, no bright star
Perseus
the warrior holding a staff, bright star Algol
Lyra
the harp, bright star Vega
Andromeda & Pegasus
Upside down horse, no bright star
Aquila
the eagle shaped like a glider, bright start Altair
Cygnus
the swan shaped like a cross, bright star Deneb
What is the name of the North Star
Polaris
Rotation
spinning on an imaginary axis
Tilt
The earth is tilted to 23 1/2 degrees
Seasons
The tilt of the Earth makes the sun hit at different directions and intensities
Vernal Equinox
March 21, sun directly above the equator
Summer Solstice
June 21, Sun directly above the Tropic of Cancer
Autumnal Equinox
September 23, Sun above equator
Winter Solstice
December 21, sun above tropic of capricorn
Northern Hemisphere summer
is between vernal and autumnal (opposite for southern)
Period
time required to complete a cycle
How long is Earths period of rotation
24 hours, one day
Earths axis points to what
Polaris
How long is Earth’s period of revolution
365 1/4 days
refraction
When light changes direction as it passes from different mediums
Refracting telescopes
large lens focuses light, then magnified by the second lens
Chromatic aberration
each color of light bends different when it goes through glass
Majority of large telescopes
are reflecting nor refracting
Who made the first reflecting telescope
Isaac Newton
Telescope
made from a concave mirror causing the light to focus
spherical aberration
problems occur when concave mirror is cut into a spherical surface.
Charge coupled device
sensitive light detector made from silicon wafer and can produce extreme detail (CCD)
radio telescope
parabolic dish that reflects radio waves to focus
Transparency
how clear the sky is
Seeing
turbulence in upper atmosphere
best way to obtain astronomical data
from space
photon
tiny packet of energy
electromagnetic waves
light, vibrating electrons in atoms
electrons
jump from energy levels to create photons
electromagnetic spectrum
arranged EMs (electromagnetic waves) in order of energy and as the frequency gets higher, the wavelength gets shorter
Order of electromagnetic waves in increasing energy
radio waves, infrared, visible light, ultraviolet, x-rays, gamma rays,
red, orange, yellow, green, blue, violet
big waves to small tighter waves
t/f all electromagnetic waves travel at 300,000 km/sec in a vacuum
true
What causes electromagnetic radiation
vibrating electrons in an atom
astronomical unit AU
Earth to sun distance
light year
distance= speed *time, distance light travels in a year
parsec
about 3.26 light years
T/F
The number of times you will orbit the Sun in your lifetime will be the same as the number of days in your life.
false
Who was the first person to realize that mirrors could be used to construct a telescope?
Isaac Newton
What causes the earth to have seasons?
The tilt of Earth’s axis allows direct sunlight to hit different places throughout the year.
t/f The biggest telescopes in use today are refracting telescopes.
false
The distance from the earth to the Sun has been called
the astronomical unit
t/f All types of electromagnetic waves travel at the same speed in a vacuum.
true
The apparent daily motion of the Sun, Moon, and stars from east to west is caused by
Earth’s rotation
What is the best way to obtain astronomical data?
use a telescope in space
What is a tiny bundle of electromagnetic energy called?
photon
t/f Reflecting telescopes often suffer from spherical aberration.
true
t/f Light leaving the earth would take a little more than one second to reach the Moon, 400,000 km away.
true
How fast do radio waves travel?
300,000 km/s
Match the bright star with the appropriate constellation.
Polaris
Ursa Minor
Match the bright star with the appropriate constellation.
Vega
Lyra
Match the bright star with the appropriate constellation.
Algol
Perseus
Match the bright star with the appropriate constellation.
Altair
Aquila
Match the bright star with the appropriate constellation.
Deneb
Cygnus
Which of the following electromagnetic waves has the most energy?
ultraviolet
Two types of telescopes are
refracting and reflecting
t/f The amount of light collected by a telescope is proportional to the area of its aperture.
true
On March 21 the Sun is directly above which location?
the Equator
t/f The Hubble Space Telescope gives us much better images than Earth-based telescopes because it is much larger than Earth-based telescopes.
false
