In astronomy, the Kennicutt–Schmidt law is an empirical relation between the surface gas density and star formation rate (SFR) in a given region. The relation was first examined by Maarten Schmidt in a 1959 paper where he proposed that the SFR surface density scales as some positive power of the local gas surface density. i.e. . In general, the SFR surface density is in units of solar masses per year per square parsec and the gas surface density in grams per square parsec . Using an analysis of gaseous helium and young stars in the solar neighborhood, the local density of white dwarfs and their luminosity function, and the local helium density, Schmidt suggested a value of (and very likely between 1 and 3). All of the data used were gathered from the Milky Way, and specifically the solar neighborhood. In 1989, Robert Kennicutt found that the H intensities in a sample of 15 galaxies could be fit with the earlier Schmidt relations with a power law index of . More recently, he examined the connection between surface gas density and SFR for a larger set of galaxies to estimate a value of . References Stellar astronomy Galaxies Star formation