It helps researchers estimate quantities such as galaxy mass, stellar populations and evolutionary history. Thus, an observed change in break mass must be due to the IMF rather than subsequent evolution. Credit: The Astrophysical Journal LettersThe effect is especially relevant when astronomers study galaxies so distant that individual stars cannot be resolved. After mass segregation, further depletion increases the characteristic mass for the best-fit Chabrier mass function, but the break mass for a Kroupa mass function is nearly invariant. (d) If an incorrect cluster age of 4 Gyr is used instead of the correct 1.25 Gyr, the break mass remains unchanged.