The origin of the 10 megagauss Zeeman features in the AM Herculis system EF Eridani

Journal Article · Thu Feb 01 04:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168385· OSTI ID:7135504

Oestreicher, R; Seifert, W; Wunner, G; Ruder, H ^[1]

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1. Landessternwarte Koenigstuhl, Heidelberg (Germany, F.R.) Tuebingen Universitaet (Germany, F.R.)

This paper examines in detail the circularly polarized absorption feature present in the spectrum of EF Eri around 6300 A, reported by Schmidt et al. (1986) and interpreted in terms of magnetically strongly shifted sigma(-) absorption of H-alpha by circumstellar matter close to the surface of the white dwarf. The discovery of the corresponding circularly polarized sigma(+) component is reported, which strongly argues in favor of the above interpretation and confirms a magnetic field value around 10 MG. From an analysis of polarization spectra at different phases, values are obtained for the radial velocities of the absorbing cold circumstellar material and at detailed information on the geometry of the system. In particular, a double change of sign in the circular polarization in both the continuum and the 6300 A feature during one period suggests the presence of two accreting spots with opposite field polarity on the same hemisphere. 13 refs.

• OSTI ID: 7135504
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 350; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION SPECTRA
BALMER LINES
BINARY STARS
DWARF STARS
MAGNETIC FIELDS
MAGNETIC STARS
POLARIZATION
RADIAL VELOCITY
SPECTRA
STAR ACCRETION
STAR EVOLUTION
STARS
VELOCITY
WHITE DWARF STARS
ZEEMAN EFFECT