If we compare a group of stars that have the same age (for example, we may look at a cluster of stars that we know all formed at the same time), we find that the most massive stars in the group are no...If we compare a group of stars that have the same age (for example, we may look at a cluster of stars that we know all formed at the same time), we find that the most massive stars in the group are no longer present on the Main Sequence, and that many star are found in the upper right corner of the plot.
