An Etymological Dictionary of Astronomy and Astrophysics
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A star whose spectrum is characterized by strong → absorption lines of ionized → calcium, Ca II (→ H and K lines), which become much stronger than the hydrogen lines of the → Balmer series. A multitude of fainter metallic lines are also present. Ca II lines strengthen to later types. → Main sequence F stars, of which → Procyon is an example, have a → surface temperature of 6,000 to 7,400°C and a mass of 1.1 to 1.4 → solar masses (Habets & Heintze, 1981, AASS 46, 193).

B, letter of alphabet used in the → → Harvard classification; → type; → star.