AST 220 – Introduction to Astronomy – Chapter 3 Questions and Answers
Optical interferometry is more in use than radio interferometry. False
Radio astronomy can only be done from up in space, due to our ionosphere. False
Like radio and optical astronomy, infrared astronomy is easily done with ground-based
telescopes. False
Due to our ozone layer, ultraviolet astronomy must be done from space. True
The mirrors for X-ray telescopes are same shape as those of optical reflectors. False
The Compton GRO was the first telescope used for our exploration of high-energy astronomy.
False
Galaxies look the same whether viewed in visible or X-ray wavelengths. False
Which type of telescope has the simplest light path? prime focus reflector
Which of the following is NOT a reason to use a reflecting telescope rather than a refractor?
Lenses are harder to focus than mirrors
What problem do refractor telescopes have that reflectors don't? chromatic aberration
The most important advantage of CCDs over film is that they record much more light in a
given exposure time.
, The primary purpose of a telescope is to collect a large amount of light and bring it into
focus.
A major advantage of Newtonian reflector over a refractor is its compact size.
Adding a secondary concave lens of carefully chosen different glass to the primary lens on a
refractor allows chromatic aberration to be reduced.
It is diffraction that limits the ____ of a telescope of a given objective diameter. Resolution
The angular resolution of an 8 inch diameter telescope is ____ times greater than that of a 2
inch diameter telescope. four
The amount of diffraction and thus the resolution of the telescope depends upon the
wavelength used and the size of the main telescope objective lens or mirror.
What is the resolution of a telescope? Its ability to distinguish two adjacent objects close
together in the sky.
Compared to a 5 inch prime focus reflector, a 5 inch Newtonian reflector will have the same
light gathering power
What is the light-gathering power of an 8 inch telescope compared to a 4 inch telescope? 4
times better
Green light has a shorter wavelength than orange light. In a 5 inch telescope, green light will
provide better angular resolution than orange light.
Optical interferometry is more in use than radio interferometry. False
Radio astronomy can only be done from up in space, due to our ionosphere. False
Like radio and optical astronomy, infrared astronomy is easily done with ground-based
telescopes. False
Due to our ozone layer, ultraviolet astronomy must be done from space. True
The mirrors for X-ray telescopes are same shape as those of optical reflectors. False
The Compton GRO was the first telescope used for our exploration of high-energy astronomy.
False
Galaxies look the same whether viewed in visible or X-ray wavelengths. False
Which type of telescope has the simplest light path? prime focus reflector
Which of the following is NOT a reason to use a reflecting telescope rather than a refractor?
Lenses are harder to focus than mirrors
What problem do refractor telescopes have that reflectors don't? chromatic aberration
The most important advantage of CCDs over film is that they record much more light in a
given exposure time.
, The primary purpose of a telescope is to collect a large amount of light and bring it into
focus.
A major advantage of Newtonian reflector over a refractor is its compact size.
Adding a secondary concave lens of carefully chosen different glass to the primary lens on a
refractor allows chromatic aberration to be reduced.
It is diffraction that limits the ____ of a telescope of a given objective diameter. Resolution
The angular resolution of an 8 inch diameter telescope is ____ times greater than that of a 2
inch diameter telescope. four
The amount of diffraction and thus the resolution of the telescope depends upon the
wavelength used and the size of the main telescope objective lens or mirror.
What is the resolution of a telescope? Its ability to distinguish two adjacent objects close
together in the sky.
Compared to a 5 inch prime focus reflector, a 5 inch Newtonian reflector will have the same
light gathering power
What is the light-gathering power of an 8 inch telescope compared to a 4 inch telescope? 4
times better
Green light has a shorter wavelength than orange light. In a 5 inch telescope, green light will
provide better angular resolution than orange light.
