Astrophysics Reference Formulas

If you entered the website here, welcome! Whilst there are many online resources that might seem that they provide similar information, the driver for can be summarized by the phrases practical and quickly accessible and time-saving convenience. The astrophysics reference list of astronomy formulas and astrophysics formulas is given below, in alphabetical order. To find what you are looking for if you can’t find it in the list, either search this webpage (e.g., using “apple-F” on a mac) or search the website using the search box in the right-hand sidebar.

List of Astrophysics Formulas
access pdf download page button

We also have a free pdf download that you can take away. It is actually 50 pages long and presents a concise list of common astrophysics formulas that we hope will serve as a useful off-line reference. However, note that the website is currently lagging behind the pdf file in the number of entries, but the website entries have more extensive explanations than the pdf file entries, often with examples. Please come back soon and/or sign-up in the right-hand sidebar for e-mail updates. The pdf file download page can be accessed by the link or button above.


  Angular Distance Between Two Points on a Sphere
  Apparent Magnitude and Absolute Magnitude Scale


  Blackbody, Planck spectrum


  Center of Mass


  Distance versus Redshift for $z\ll 1$
  Doppler Broadening Thermal Line Width
  Doppler Shift for Light and Radiation


  Eddington Luminosity
  Escape velocity
  Event Horizon of a Black Hole

  eV to kg Conversion


  Fine Structure Constant
  FWHM Gaussian FWHM Calculation


  GeV to kg Conversion
  Gravitational Radius


  Inverse Square Law Radiation


  Kelvin to keV Conversion
  keV to Kelvin Conversion
  Kepler’s Laws
  kg to eV Conversion
  kg to GeV Conversion
  kg to MeV Conversion


  Light-Crossing Times
  Lorentz Transformations in Special Relativity
  Lorentzian FWHM Calculation


  Maxwell’s Equations
  Maxwell-Boltzman velocity distribution
  MeV to kg Conversion


  Orbital Velocity (various useful forms)
  Orbital Period


  Parallax – Definition of Parallax


  Rayleigh-Jeans Law (Low frequency limit for blackbody)
Reduced Mass
 Root Mean Square Velocity of Particles in a Gas with Maxwellian Velocity Distribution


  Schwarzschild Radius
  Solid Angle Definition
  Stefan-Boltzmann (flux versus temperature for a blackbody)


  Wien Displacement Law
  Wien’s Law Spectrum (high-frequency limit of blackbody spectrum)