Chapter 3 Astronomy HSU
1 nanometer (nm) is
10-9m
A Newtonian telescope consists of the following types of mirrors:
one concave and one flat mirror
a___________ is a device that separates the light from stars and other objects according to wavelength in order to produce a spectrum
spectrograph
A recorder is part of a radio telescope
true
Chromatic aberration occurs in a refracting telescope when
the different colors of light do not all come to the same focal point
How is a Cassegrain reflecting telescope constructed?
A concave primary mirror and convex secondary mirror that reflects light back through a hole in the primary mirror
In a telescope, to what does the term “aberration” refer?
A defect in design that blurs or distorts the image
Modern astronomy would be possible without extensive use of computers
true
Neutrinos are important to our understanding of the early Universe.
True
One major difference between radio waves and light is that
radio waves have lower frequencies than light waves.
Radio waves travel through space at what speed?
At the speed of light, 3 × 108 m/s
Schmidt telescopes are used mostly for
photographing wide areas of the night sky.
The Earth’s atmosphere is transparent to which of the following types of electromagnetic radiation?
Radio waves
The IRAS satellite, placed in orbit in 1983 to survey the whole sky, detected which kind of electromagnetic radiation?
Infrared
The speed of light in space is
3 × 108 meters per second, independent of the speed of the source.
Violet light differs from red light in that
violet light has a shorter wavelength than red light.
What are the basic parts of a Schmidt telescope?
A spherical, concave primary mirror and a glass corrector plate.
What is the main reason for using several radio telescopes together as an interferometer?
To obtain much better angular resolution (sharpness) of the images
What is the relationship between color and wavelength for light?
Wavelength increases from violet to red.
Which of the following is an electromagnetic wave?
Microwave
Which of the following types of electromagnetic radiation has the shortest wavelength?
Gamma rays
Which type of telescope uses a lens as the main optical element?
A refracting telescope
Who first showed that light does not travel at infinite speed?
Ole Roemer in 1675
Who was the first person to suggest that light is an electromagnetic wave?
James Clerk Maxwell
Who was the first astronomer to build and use a telescope to observe the night sky?
Galileo