The discovery of magnetically controlled circumstellar matter in the helium-weak stars HD 5737 and HD 79158
Creators
- 1. Western Ontario Univ., London (Canada)
- 2. NASA, Goddard Space Flight Center, Greenbelt, MD (USA)
- 3. Washington Univ., Seattle (USA)
- 4. Ecole Normale Superieure, Paris (France)
- 5. New Mexico Institute of Mining and Technology, Socorro (USA)
Description
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. 33 refs
Additional details
Publishing Information
- Journal Title
- Astrophysical Journal
- Journal Volume
- 348
- Series
- Astrophys. J.
- Journal Page Range
- 242-252
- ISSN
- 0004-637X
- CODEN
- ASJOA
INIS
- Country of Publication
- United States
- Country of Input or Organization
- United States
- INIS RN
- 21055567
- Subject category
- S79: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY;
- Descriptors DEI
- CHEMICAL COMPOSITION; HELIUM; MAGNETIC FIELDS; MAGNETIC STARS; MORPHOLOGICAL CHANGES; POLARIMETERS; SPECTROSCOPY; STELLAR MAGNETOSPHERES; ZEEMAN EFFECT
- Descriptors DEC
- ATMOSPHERES; ELEMENTS; NONMETALS; RARE GASES; STARS; STELLAR ATMOSPHERES