The discovery of magnetically controlled circumstellar matter in the helium-weak stars HD 5737 and HD 79158

Abstract

view Abstract Citations (57) References (28) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Discovery of Magnetically Controlled Circumstellar Matter in the Helium-weak Stars HD 5737 and HD 79158 Shore, Steven N. ; Brown, Douglas N. ; Sonneborn, George ; Landstreet, John D. ; Bohlender, David A. Abstract The paper reports the discovery, using combined IUE spectroscopy and Zeeman polarimetric magnetic field measurements, of magnetically controlled circumstellar material in two helium-weak stars. HD 5737 = Alpha Sculptoris is, except for its extreme helium deficiency, similar to the He weak sn star HD 21699. A unique period for the magnetic and C IV and Si IV variations of 21.65 days is reported. The effective (longitudinal) field nulls coincide extremely well with C IV line strength maxima. The magnetic field and equatorial trapped plasma are highly oblique to the rotation axis (about 70 deg), and the line variations appear to be stable. Similar magnetospheric variations in HD 79158 = 36 Lyncis have been discovered, for which no period had been previously available. The period is 3.84 days, yet it too displays magnetic-equatorial plasma. The magnetospheric axis is highly oblique to the rotation axis, around 80 deg. Publication: The Astrophysical Journal Pub Date: January 1990 DOI: 10.1086/168233 Bibcode: 1990ApJ...348..242S Keywords: A Stars; Magnetic Stars; Peculiar Stars; Stellar Envelopes; Stellar Magnetic Fields; Ultraviolet Spectroscopy; Astronomical Spectroscopy; Polarimetry; Stellar Magnetospheres; Zeeman Effect; Astrophysics; STARS: INDIVIDUAL HENRY DRAPER NUMBER: HD 5737; STARS: INDIVIDUAL HENRY DRAPER NUMBER: HD 79158; STARS: MAGNETIC; STARS: PECULIAR A; ULTRAVIOLET: SPECTRA full text sources ADS | data products SIMBAD (9) MAST (1) INES (1)