Reflective
Refractive
Spectro
scopy
Space
Large
telescopes
How Optical
works
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$200
Draw a convex lens
$400
The lens are made of glass and the larger
they are , the more heavy and more flawed
they can be.
Why are refractive telescopes
usually smaller than
reflective?
$600
Reflective
A telescope with a convex
mirror and an eyepiece on the
side is a
$800
They gather more light and have better
resolution
Why might you want a larger
scope than a smaller one?
$1000
The Cassegrain needs a hole drilled in the
middle of the primary mirror for the
eyepiece and its secondary mirror in convex
rather than flat.
Why is a Newtonian reflector
easier to build than a Cassegrain?
$200
Reflection
The process when Photons
bounce off a polished surface
$400
Refraction
The tendency of a wave to
bend as it passes from one
transparent medium to
another is
$600
Chromatic aberration
Fuzziness in your lens is
caused by
$800
CCD’s are faster at capturing light so
shorter exposure time. The image is digital,
no wait time to be developed. The image is
stored on computers, so can be transmitted
via the Internet
Why is a CCD better than photography
for telescopes?
$1000
Reflectors use a concave mirror to reflect
light back to a focus, refractors use a
convex lens to bend light to a focus.
Compare how a reflector
makes an image versus a
refractor
$200
radio
The lowest energy EM
radiation is
$400
Most information we receive about the
Universe comes in EM waves, especially
light. We can get temperature, compostion
and motion from a spectrum
Why do astronomers relie on
spectroscopy?
$600
An emission spectrum of bright lines
(Kirchoff’s 2nd law)
A nebula is a low density
cloud of hot gas, what is its
spectrum?
$800
Using a prism or diffraction gratings
where thin slits diffract light.
Describe two ways that light
is separated out into its
component colors for
spectroscopy
$1000
1st Law: dense hot objects create a continuous
spectrum
2nd law: low density gas gives off bright
emission lines
3rd law: cool thin gas creates dark lines in the
spectrum
Describe Kirchoff’s three
laws
$200
Turbulence or star twinkling
Adaptive optics help correct
$400
NO.
Is it true that the HST is the
Largest telescope ever built?
$600
Infrared and Ultraviolet
Besides visible light, Hubble
does work in what two other
wavelengths?
$800
X-rays
The Chandra uses which kind
wavelength to form images?
$1000
Adaptive optics are for poor visibility due
to atmospheric blurring, Hubble is in space!
Why doesn’t the Hubble
Telescope need adaptive
optics?
$200
To collect light and bring it to focus
The primary purpose of
telescopes is to
$400
Poor resolution due to the large wavelength
What is the downside of radio
telescopes?
$600
Interferometry
Using multiple telescopes to
enhance resolution via
computers is called
$800
The atmosphere blocks most UV radiation
Why is UV astronomy hard to
do from the ground?
$1000
Can be used in daytime and night. Less
effected by weather/ Allow us to see objects
at different wavelength than visible light.
Name three ways that radio
telescopes have an advantage
over optical telescopes.
$200
To get above the influences of our atmosphere
Why do we put telescopes in
space?
$400
resolution
The ability to distinguish between two
adjacent objects is
$600
The resolution is 2x’s as sharp and can now
detect 4x’s as dim of objects.
How does doubling the
diameter effect resolution and
light?
$800
Stars do not twinkle in space but as they pass
through our atmosphere the light is shifted by
turbulence.
Why do stars appear to twinkle?
$1000
The object has already flipped over since
the eyepiece lies behind the focal point.
Why is the image in a telescope
eyepiece inverted?