Published online by Cambridge University Press: 12 April 2016
The present discussion of hot magnetic CP stars is restricted to 17000 K < Teff < 30 000 K, the upper limit being the temperature up to which magnetic fields can be observed, the lower limit defining the boundary between He-rich and He-poor stars.
All of the hot magnetics belong to the class of intermediate helium stars which is defined by nH/nHe, < 3 (number ratio, Hunger 1975). Walborn (1983) lists 23 stars of this class, mostly with nH/nHe, ≈ 1, and of spectral type B2 V. Magnetic fields, so far, have been discovered in 7 of them (Borra et al. 1983). All but one of these are spectrum variables, with periods 0.9<P/day<1.7 (except one with P = 9.5 d), (Pedersen, 1979) and with rotational velocities of the order of v sin i ≈ 150 km/s which are compatible with the (P, v sin i)-relation of stars near the main sequence; i.e. these stars are oblique rotators.