Lecture 6 pt 1 Flashcards
What are the three powers of a telescope?
Light gathering power, resolving power, and magnifying power
What is Angular Resolution?
a measure of the ability
to separate two closely-spaced lights. The human eye has an angular resolution of about 1 arc minute (1/60th of a degree).
What is a refracting telescope?
A telescope that forms images by bending (refracting) light with a lens. Refracting telescopes suffer from optical distortion
What is a reflecting telescope?
A telescope that forms images by reflecting light with a mirror
What is the best location for a telescope?
Far away from civilization to avoid light pollution
What is light pollution
The illumination of the night sky by waste light from cities and outdoor lighting, which
prevents the observation of faint objects
What is a charge-coupled device (CCD)
an electronic device consisting of a large array of light-sensitive elements. CCD images can detect both bright and faint objects in a single exposure
What collects light in a reflecting telescope?
A mirror
A mirror forms an image in:
a reflecting telescope
What is the primary reason for making telescopes larger?
To collect more light so faint objects can be seen
What does better angular resolution mean?
You can see more detail in images
What advantages come from putting a telescope in space?
Wavelengths of light that do not penetrate Earth’s atmosphere can be seen, and images may be sharper without moving air to blur them
What are the 2 most important properties for optical telescopes?
a large collecting area and high angular resolution
True or False: New technologies will soon allow astronomers to use x-ray telescopes on Earth’s surface.
False, x-rays are absorbed by the atmosphere and don’t reach Earth’s surface
