Ap and Bp stars

Ap and Bp stars are peculiar stars (hence the "p") of types A and B which show overabundances of some metals, such as strontium, chromium and europium; in addition, larger overabundances are often seen in praseodymium and neodymium. These stars have a much slower rotation than normal for A and B-type stars, although some exhibit rotation velocities up to about 100 kilometers per second.