4.1 EM Spectrum. Wavelength : distance between two successive crests or troughs. Light : is a wave of wavelength ranging between 400 nm (violet) to 660 nm (red). Electromagnetic Radiation.
Light: is a wave of wavelength ranging between 400 nm (violet) to 660 nm (red)
The angular size of the Moon is 0.5º (1/2º )
The angular size of the Sun is also 0.5º (1/2º )
1º = 60 arcminutes = 60'
1' = 60 arcseconds = 60''
So 1º = 60x60 = 3,600 arcseconds = 3,600''
Test question: What is the angular size of the Moon ( 0.5°) expressed in arcseconds?
d = linear size of object
theta = angular size of object (in radians)
L = distance to the object
4.5 Light Gathering Power
What is special about Mauna Kea?
As the magnification increases, the field of view decreases
A telescope of 1-meter focal length. Calculate its magnification if the eyepiece has a focal length of 40 mm.
Compare the collecting power of the 10-meter telescope with that of the 5-meter telescope.