Richter magnitude scale Richter correlation tables based on Richter standard seismic event (formula_26, formula_27, formula_28). Below, formula_29 is the epicentral distance (in kilometers unless otherwise specified). The Lillie empirical formula: Where formula_31 is the amplitude (maximum ground displacement) of the P-wave, in micrometers, measured at 0.8 Hz. For distances formula_32 less than 200 km, and for distances between 200 km and 600 km, where formula_31 is seismograph signal amplitude in mm and formula_32 is in km. The Bisztricsany (1958) empirical formula for epicentral distances between 4˚ to 160˚: Where formula_38 is the duration of the surface wave in seconds, and formula_39 is in
Absolute magnitude and a difference of n magnitudes in absolute magnitude corresponds to a luminosity ratio of 100. For example, a star of absolute magnitude M=3 would be 100 times more luminous than a star of absolute magnitude M=8 as measured in the V filter band. The Sun has absolute magnitude M=+4.83. Highly luminous objects can have negative absolute magnitudes: for example, the Milky Way galaxy has an absolute B magnitude of about −20.8. An object's absolute bolometric magnitude represents its total luminosity over all wavelengths, rather than in a single filter band, as expressed on a logarithmic magnitude scale. To convert