Astronomy 110G: Useful Formulas II
Formula	Variables
Rules of scientific notation	mathematics
Units conversion	conversion factors will be provided as necessary, as on quizzes
Circumference of a circle	C = 2 R, where R = radius
Area of a circle	A = R2, where R = radius
Apparent visual magnitude scale	relative magnitude and brightness
Flux (inverse square) law	luminosity, distance, area
Newton's law of gravitation	mass and distance
Kepler's Three Laws	properties of planetary orbits
Parallax relation	observatory shift, object shift, distance to object
Blackbody relation	temperature and wavelength
Frequency relation	energy, frequency, Planck's constant
Wavelength relation	energy, wavelength, Planck's constant, the speed of light
Doppler relation	radial velocity, the speed of light, observed and rest wavelengths
Definition of an element	number of protons in the nucleus of the atom
Stellar properties	luminosity, temperature, radius
Stellar temperatures	OBAFGKMLT
Energy relation (Einstein)	energy, mass, the speed of light
Hubble's law	H0, velocity and distance of galaxies