Charles Francis Richter developed a logarithmic scale to measure intensity. The name "magnitude" for this measurement came from Richter's childhood interest in astronomy - astronomers measure the intensity of stars in magnitudes. Gutenberg's contribution was substantial, but his aversion to interviews contributed to his name being left off the scale. After the publication of the proposed scale in 1935, seismologists quickly adopted it for use in measuring the intensity of earthquakes. Richter remained at the Carnegie Institute until 1936, when he obtained a post at the California Institute of Technology, where Beno Gutenberg worked. Gutenberg and Richter published "Seismicity of the Earth" in
Absolute magnitude corresponds to absolute bolometric magnitude 4.74. Placing a radiation source (e.g. star) at the standard distance of 10 parsecs, it follows that the zero point of the apparent bolometric magnitude scale corresponds to irradiance . Using the IAU 2015 scale, the nominal total solar irradiance ("solar constant") measured at 1 astronomical unit () corresponds to an apparent bolometric magnitude of the Sun of −26.832. Following Resolution B2, the relation between a star's absolute bolometric magnitude and its luminosity is no longer directly tied to the Sun's (variable) luminosity: where The new IAU absolute magnitude scale permanently disconnects the scale from