Astrophysics and Cosmology Flashcards
(12 cards)
What is a Planet?
Objects with mass sufficient for their own gravity to force them to take a spherical shape, where no nuclear fusion occurs, and the object has cleared its orbit of other objects.
What are Dwarf Planets?
Planets where the orbit has not been cleared of other objects.
What is a planetary satellite?
Bodies that orbit a planet.
What are asteroids?
Objects which are too small and uneven in shape to be planets, with a near circular orbit around the sun.
What are comets?
Small, irregularly sized balls of rock, dust, and ice. They orbit the sun in eccentric elliptical orbits.
What is an Emission Line Spectra?
Each element produces a unique emission line spectrum because of the unique set of energy levels associated with its electrons. It appears as a series of coloured lines on a black background.
What is a continuous line spectra?
All visible wavelengths of light are present. They are produced by atoms of solid heated metals.
What is an absorption line spectra?
A series of dark spectral lines against the background of the continuous spectrum, with each line corresponding to a wavelength of light used to excite atoms of that element.
What are diffraction gratings?
Diffraction gratings are components with regularly spaced slits that can diffract light. Different colours of light have different wavelengths, and so will be diffracted at different angles.
What is Wein’s Law?
It states that the black body radiation curve for different temperatures peaks at a wavelength inversely proportional to the temperature of the object.
Temperature of K in degrees C
-273K
