An Etymological Dictionary of Astronomy and Astrophysics
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A chemically peculiar A- or early F-type star showing an overabundance of → heavy elements and an underabundance of calcium and scandium. An Am star cannot receive a unique spectral type, as different methods (using the metallic lines, the hydrogen Balmer lines, and the calcium Ca II K-lines) yield three different spectral types. Contrarily to Ap stars, Am stars do not have significant external magnetic fields. Their rotational velocities are about 100-120 km s^-1 smaller than those of → Ap stars.

A for the spectral type, m for → metal; → star.

Stars for the observation of which telescope time has been awarded.

→ program; → star.