Telescopes Flashcards
What are the three types of telescope?
Refracting and reflecting and combination
What is a refracting telescope?
Uses a lens to refract parallel rays onto a single focal point
What is a reflecting telescope?
Uses a parabolic mirror to reflect parallel rays onto a focal point
What is light gathering power proportional to?
The surface area of the telescope
What are some issues for refracting telescopes?
Image distortion due to shape
Difficult to make a lense for a wide range of wavelengths
What is a combination telescope?
Uses a combination of a parabolic mirror and a lens to focus rays onto a single point
What is the distance between the focal points of two objects?
l = fα
Where α is the angle between the incident rays
What is the focal ratio of a lens?
f/D
What is the smallest angle for which two stars can be distinguished?
α_min = 1.22λ/D
What is adaptive optics?
A technique used to counteract the distortions of the atmosphere using deformable mirrors
What is the angular magnification?
M =α2/α1=f1/f2
