Initial mass function (IMF)

(Last edited: Saturday, 30 September 2023, 8:59 PM)

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Short Definition:

The initial mass function (IMF) describes the distribution of stellar masses as a large cluster of stars is newly formed and is based on an average from stars in our Milky Way.

This function is useful for understanding the formation of stellar systems and their evolution. In most cases, the initial mass function is shown with a logarithmic scale.

Derailed Definition:

The initial mass function shows few massive stars which are more massive than the sun, while sun-sized stars are more abundant and stars that are smaller than the sun are quite common (this trend does not continue linear the smaller they get):

The function can be described by using the following law:

IMF = constant x m^(-α)

where m = initial star mass and α = slope of the logarithmic plot.

Until this point in time, it is not certain if the IMF varies in extreme situations and if the calculation based on our Milky Way can be unconditionally applied to other galaxies.


initial - Latin initialis ("initial, incipent, of the beginning")

mass - old French masse (" lump, heap, pile; crowd, large amount")

function - Latin functionem (" a performance, an execution")

Sample sentences:

There are different curve forms of the initial mass function based on the way the alpha and the constant are calculated.


French: fonction de masse initiale

German: Anfangsmassenfunktion

Polish: początkowa funkcja masy

Swedish: funktion för dem ursprungliga massan

Links to Videos/Articles:

» Dictionary of Space Concepts