Download VI. Preferred Location of Telescopes

Telescopes
I. Refraction: Refraction is the _____________ of light as it passes
through glass.
II. Reflection: Reflection occurs when light _____________ off of a
mirror.
F
f
I. Refraction: Refraction is the ___bending____ of light as it passes
through glass.
II. Reflection: Reflection occurs when light _____________ off of a
mirror.
F
f
I. Refraction: Refraction is the ___bending____ of light as it passes
through glass.
glass lens
focal point
focal length
II. Reflection: Reflection occurs when light _____________ off of a
mirror.
F
f
I. Refraction: Refraction is the ___bending____ of light as it passes
through glass.
glass lens
focal point
focal length
II. Reflection: Reflection occurs when light ___bounces ___ off of a
mirror.
F
f
I. Refraction: Refraction is the ___bending____ of light as it passes
through glass.
glass lens
focal point
focal length
II. Reflection: Reflection occurs when light ___bounces ___ off of a
mirror.
focal point
mirror
F
f
focal length
Light focuses at different points.
Light focuses at one point!!
Chromatic Aberration with Glass Lenses
Bad news!!
Remember
Newton’s prism!
III. Telescopes:
A. A ____________ telescope uses glass lenses to collect and focus
the light.
B. The primary component of a ____________ telescope that
collects and focuses the light is a mirror.
III. Telescopes:
A. A _refracting__ telescope uses glass lenses to collect and focus
the light.
main objective
B. The primary component of a ____________ telescope that
collects and focuses the light is a mirror.
III. Telescopes:
A. A __refracting__ telescope uses glass lenses to collect and focus
the light.
main objective
B. The primary component of a __reflecting__ telescope that
collects and focuses the light is a mirror.
main objective
IV. Two Main Types of Reflecting Telescopes:
A. Newtonian
1. The original reflecting telescope. Made by Isaac Newton
2. Simple. Commonly used in smaller amateur telescopes.
B. Cassegrain
1. More compact.
2. Commonly used for the
larger telescopes
IV. Two Main Types of Reflecting Telescopes:
A. Newtonian
1. The original reflecting telescope. Made by Isaac Newton
2. Simple. Commonly used in smaller amateur telescopes.
Newton
polished his
mirror from a
solid piece of
metal.
B. Cassegrain
1. More compact.
2. Commonly used for the
larger telescopes
V. Why Do Astronomers Want to Build Larger and Larger Telescopes?
A. The larger the primary mirror of a telescope, the more _______ it can
collect. This means it can see ____________ objects and take images
in a ___________ period of time.
B. The larger the primary mirror, the better the ___________. Larger
telescopes can see more detail.
  1.22
l
D
θ = angular separation (in radians)
l = wavelength of light being collected
D = diameter of the primary mirror or lens
V. Why Do Astronomers Want to Build Larger and Larger Telescopes?
A. The larger the primary mirror of a telescope, the more __light__ it can
collect. This means it can see ____fainter___ objects and take images
in a ___shorter___ period of time.
B. The larger the primary mirror, the better the ___________. Larger
telescopes can see more detail.
  1.22
l
D
θ = angular separation (in radians)
l = wavelength of light being collected
D = diameter of the primary mirror or lens
V. Why Do Astronomers Want to Build Larger and Larger Telescopes?
A. The larger the primary mirror of a telescope, the more __light__ it can
collect. This means it can see ____fainter___ objects and take images
in a ___shorter___ period of time.
B. The larger the primary mirror, the better the __resolution__. Larger
telescopes can see more detail.
  1.22
l
D
θ = angular separation (in radians)
l = wavelength of light being collected
D = diameter of the primary mirror or lens
V. Why Do Astronomers Want to Build Larger and Larger Telescopes?
A. The larger the primary mirror of a telescope, the more __light__ it can
collect. This means it can see ____fainter___ objects and take images
in a ___shorter___ period of time.
B. The larger the primary mirror, the better the __resolution__. Larger
telescopes can see more detail.
  1.22
l
D
the smaller the better
θ = angular separation (in radians)
l = wavelength of light being collected
D = diameter of the primary mirror or lens
the bigger the better
VI. Preferred Location of Telescopes
A. The turbulence of the atmosphere causes the light passing
through it to be ____________. We see this as twinkling of the
stars. Astronomers see this as a problem that prevents them
from obtaining nice clear images.
B. As a result, most major observatories are place on the top of
_____________ to get above as much of the Earth’s atmosphere
as possible.
C. Even on the tops of mountains, there is distortion from the Earth’s
atmosphere, plus the Earth’s atmosphere absorbs many
wavelengths of light. The ultimate, distortion-free environment is
to observe from ______________. The primary drawback of
observing from space is the expense.
VI. Preferred Location of Telescopes
A. The turbulence of the atmosphere causes the light passing
through it to be __refracted__. We see this as twinkling of the
stars. Astronomers see this as a problem that prevents them
from obtaining nice clear images.
B. As a result, most major observatories are place on the top of
_____________ to get above as much of the Earth’s atmosphere
as possible.
C. Even on the tops of mountains, there is distortion from the Earth’s
atmosphere, plus the Earth’s atmosphere absorbs many
wavelengths of light. The ultimate, distortion-free environment is
to observe from ______________. The primary drawback of
observing from space is the expense.
VI. Preferred Location of Telescopes
A. The turbulence of the atmosphere causes the light passing
through it to be __refracted__. We see this as twinkling of the
stars. Astronomers see this as a problem that prevents them
from obtaining nice clear images.
B. As a result, most major observatories are place on the top of
___mountains___ to get above as much of the Earth’s atmosphere
as possible.
The Keck telescope on Mauna Kea in Hawaii sit at 13,600 ft … above 40% of the atmosphere. *
C. Even on the tops of mountains, there is distortion from the Earth’s
atmosphere, plus the Earth’s atmosphere absorbs many
wavelengths of light. The ultimate, distortion-free environment is
to observe from ______________. The primary drawback of
observing from space is the expense.
Keck Telescopes on Mauna Kea, Hawaii
Kitt Peak National Observatory, Arizona
La Silla Paranal Observatory in Chile
VI. Preferred Location of Telescopes
A. The turbulence of the atmosphere causes the light passing
through it to be __refracted__. We see this as twinkling of the
stars. Astronomers see this as a problem that prevents them
from obtaining nice clear images.
B. As a result, most major observatories are place on the top of
___mountains___ to get above as much of the Earth’s atmosphere
as possible.
The Keck telescope on Mauna Kea in Hawaii sit at 13,600 ft … above 40% of the atmosphere.
C. Even on the tops of mountains, there is distortion from the Earth’s
atmosphere, plus the Earth’s atmosphere absorbs many
wavelengths of light. The ultimate, distortion-free environment is
to observe from _________. The primary drawback of observing
from space is the expense.
VI. Preferred Location of Telescopes
A. The turbulence of the atmosphere causes the light passing
through it to be __refracted__. We see this as twinkling of the
stars. Astronomers see this as a problem that prevents them
from obtaining nice clear images.
B. As a result, most major observatories are place on the top of
___mountains___ to get above as much of the Earth’s atmosphere
as possible.
The Keck telescope on Mauna Kea in Hawaii sit at 13,600 ft … above 40% of the atmosphere.
C. Even on the tops of mountains, there is distortion from the Earth’s
atmosphere, plus the Earth’s atmosphere absorbs many
wavelengths of light. The ultimate, distortion-free environment is
to observe from __space__*. The primary drawback of observing
from space is the expense.
Hubble Space Telescope
VII. Adaptive Optics
A. This is a method to compensate for the atmosphere’s turbulence
that is _______________ than sending the telescope into space.
B. A fairly bright star is monitored. As this bright star moves around
due to the turbulence, a deformable secondary mirror makes
___________ of adjustments ____________to correct the
image.
VII. Adaptive Optics
A. This is a method to compensate for the atmosphere’s turbulence
that is __less expensive__ than sending the telescope into space.
B. A fairly bright star is monitored. As this bright star moves around
due to the turbulence, a deformable secondary mirror makes
___________ of adjustments ____________to correct the
image.
VII. Adaptive Optics
A. This is a method to compensate for the atmosphere’s turbulence
that is __less expensive__ than sending the telescope into space.
B. A fairly bright star is monitored. As this bright star moves around
due to the turbulence, a deformable secondary mirror makes
__hundreds__ of adjustments __per second__to correct the
image.
VII. Adaptive Optics
A. This is a method to
compensate for the
atmosphere’s turbulence
that is _______________
than sending the telescope
into space.
B. A fairly bright star is
monitored. As this bright
star moves around due to
the turbulence, a
deformable secondary
mirror makes __________
_________ adjustments to
correct the image.
VII. Adaptive Optics
A. This is a method to
compensate for the
atmosphere’s turbulence
that is __less expensive__
than sending the telescope
into space.
B. A fairly bright star is
monitored. As this bright
star moves around due to
the turbulence, a
deformable secondary
mirror makes __________
_________ adjustments to
correct the image.
VII. Adaptive Optics
A. This is a method to
compensate for the
atmosphere’s turbulence
that is __less expensive__
than sending the telescope
into space.
atmosphere
telescope
B. A fairly bright star is
monitored. As this bright
star moves around due to
the turbulence, a
deformable secondary
mirror makes _rapid and
ongoing ___ adjustments to
correct the image.
CCD (charge coupled device)
Viewing Uranus With and Without Adaptive Optics
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