The SN Stars: Magnetically Controlled Stellar Winds Among the Helium-Weak Stars

The authors report observations of magnetically controlled stellar mass outflows in three helium-weak sn stars: HD 21699 = HR 1063, HD 5737 = α Scl, and HD 79158 = 36 Lyn. IUE observations show that the C IV resonance doublet is variable on the rotational timescale but that there are no other strong-spectrum variations in the UV. Magnetic fields, which reverse sign on the rotational timescale, are present in all three stars. The authors interpret this phenomenology in terms of jet-like mass loss above the magnetic poles and discuss these objects in the context of a general survey of the C IV and Si IV profiles of other more typical helium-weak stars.