A peculiar star (hence the suffix ‘p’) of spectral type A that has much stronger absorption lines than normal of elements such as manganese, mercury, silicon, chromium, strontium, and europium; also known as a peculiar A star. Such stars have unusually strong magnetic fields, thousands of times stronger than the Sun's typical surface field. This leads to certain elements being localized in spots, similar to sunspots. As the star rotates the spectral features therefore vary. Hotter and cooler versions of Ap stars are, respectively, Bp and Fp stars.
Subjects: Astronomy and Astrophysics.