Textbook Notes (367,993)
Canada (161,547)
Astronomy (53)
AS101 (52)
Chapter 4

Chapter 4 Textbook Definitions

2 Pages
Unlock Document

Shohini Ghose

Chapter 4: Astronomical Telescope and Instruments Electromagnetic Radiation – changing electric and magnetic fields that travel through space and transfer energy from one place to another; ex. Light and radio waves Wavelength (λ) – the distance between successive peaks or troughs of a wave, usually represented by a lowercase Greek lambda Nanometre (nm) – a unit of distance equalling one-billionth of a metre, commonly used to measure the wavelength of light Angstrom (Å) – a unit of distance commonly used to measure the wavelength of light Infrared (IR) – the portion of the electromagnetic spectrum with wavelengths longer than red light, ranging from 700nm to about 1mm, between visible light and radio waves Ultraviolet (UV) – the portion of the electromagnetic spectrum with wavelengths shorter than violet light, between visible light and X-rays X-rays – electromagnetic waves with wavelengths shorter than ultraviolet light Gamma Rays – the shortest-wavelength electromagnetic waves Photon – a quantum of electromagnetic energy that carries an amount of energy that increases proportionally with its frequency but decreases proportionally with its wavelength Atmospheric Window – wavelength region in which our atmosphere is transparent – at visual, radio, and some infrared wavelengths Refracting Telescope – a telescope that forms images by bending (refracting) light with a lens Reflecting Telescope – a telescope that forms images by reflecting light with a mirror Primary Lens – in a refracting telescope , the largest lens Primary Mirror – in a reflecting telescope, the largest mirror Eyepiece – a short-focal-length lens used to enlarge the image in a telescope; the lens nearest the eye Focal Length – the focal length of a lens or mirror is the distance from the lens or mirror to the point where it focuses parallel rays of light Chromatic Aberration – a distortion found in refracting telescopes because lenses focus different colours at slightly different distances; images are consequently surrounded by colour fringes Optical Telescope – telescope that gathers visible light Radio Telescope
More Less

Related notes for AS101

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.