A unit of temperature equal to one million kelvins. This unit is used in astrophysics; temperatures in megakelvins are found in the interiors of stars or in highly excited plasmas. The reciprocal megakelvin (MK-1) is used in colorimetry
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}