Part Two Flashcards
(58 cards)
Absorption spectrum
a colour spectrum with dark absorption lines (happens when an intervening cool gas absorbs certain wavelengths from the original light source)
Continuous spectrum
when light of all wavelengths is emitted without interruption
Emission lines
single frequencies emitted by particular atoms (heated gas)
Kirchoff’s laws
continuous, emission and absorption spectrum
What does a telescope do?
Magnifies, gathers light and sees fine detail
Refraction
the bending of a beam of light as it passes from one transparent medium to another (air –> glass)
Why are modern telescopes reflectors?
a lens needs two optically acceptable surfaces, a mirror only needs one; some light travelling through a lens gets absorbed (bad)
How does telescope size affect observing?
Larger telescopes gather more light, therefore having better resolution
Photometry
measurement of brightness
Angular resolution
if the wavelength is longer, there’s more diffraction; if opening is larger, there’s less diffraction
angular resolution = 0.25*wavelength(micrometers)/mirror diameter(m)
Diffraction
when light spreads out as it passes a corner or through an opening
Interferometry
combining info from several spread out dishes as if they came from one dish
Refraction
other side of mirror
Reflection
same side of mirror
Grazing incidence
how x-rays are focused; reflected at a very shallow angle
Cherenkov light
caused by gamma rays interacting with the atmosphere which causes “shower particles”
Quantized levels
orbits that an electron is allowed to orbit in
Photon’s energy
E = hf (E = energy, h = constant, f = frequency), the higher the frequency, the higher the energy E = E2 - E1 (energy difference between orbits)
Electron jumping up
absorption lines
Electron moving down
emission lines
When does the electron leave the atom?
at 13.6 electron volts
Ground state
n = 1
Excited states
begin at n = 2
Lyman series
transition to/from n = 1 (Lyman alpha: n=2 n= 1)
