ASTR 1P01 Study Guide - Final Guide: Electromagnetic Radiation, Photon, Watt

• School: Brock University
• Department: Astronomy
• Course: ASTR 1P01
• Professor: Bozidar Mitrovic

Document Summary

Lights and telescopes: all information about stars is obtained from the light they emit, speed of propagation> c=300 000 km/s, electromagnetic spectrum (1 nm= 10-9 m, gamma rays, x- rays, uv, violet, blue, green, yellow, orange, red. Wavelengths of visible light range from 400nm(violet) to 700nm (red) White light from sun is a mixture of all visible wavelengths. Earth"s highest atmosphere blocks gamma rays, x rays and some radio waves: ozone layer blocks most of uv radiation. , e=photon energy, = wavelength of radiation, h= 6. 63 x 10-34 ws2(planck"s constant), c= 3. 00 x 108 m/s (speed of light in a vacuum) The shorter the wavelength, the higher the photon energy: telescopes, the amount of light energy that enters the eye is small and limited by size of eye, b= , b=brightness (energy received per unit area/time), l= luminosity (energy output per unit time), d=distance from the source: more light can be collected by using.