What Does ZAMS Stand For?

ZAMS stands for Zero Age Main Sequence

ZAMS, or Zero Age Main Sequence, refers to the initial phase of stellar evolution when a star first reaches the main sequence on the Hertzsprung-Russell diagram. During this stage, a star has fully contracted to hydrostatic equilibrium, and nuclear fusion of hydrogen into helium begins in its core. ZAMS represents a pivotal moment in a star's lifecycle, marking the transition from pre-main sequence to stable hydrogen-burning phase.