php require("/home/jeffery/public_html/astro/star/pleiades_1a.shtml");?> The Pleiades are an example of a star cluster of the type open cluster. The other type is globular cluster.
Features:
Note relative to age of the observable universe = 13.797(23) Gyr (Planck 2018), tens of millions of years is almost an instant in cosmic time. Of course, tens of millions of years is very long relative to all of human history.