Transients in the He I lambda 6678 line of Lambda Eri (B2e) - magnetic quasi-cycles

Journal Article · Sun Oct 01 04:00:00 EDT 1989 · Astrophysical Journal, Supplement Series; (USA)

DOI:https://doi.org/10.1086/191378· OSTI ID:7017903

Smith, M A ^[1]

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1. National Solar Observatory, Tucson, AZ (USA)

An extensive spectroscopic monitoring program was conducted, at the McMath solar telescope, on the He I lambda 6678 line profile of the B2e star Lambda Eri, covering over 840 high-quality observations on 184 nights from 1984 to 1988. The existence of two nonradial pulsation (NRP) modes in Lambda Eri, and the search (with a negative result) for an anticorrelation between NRP amplitude and lambda 6678 (and secondarily H alpha) emission are discussed. The transients present in lambda 6678 during both the quiescent and He I active states are described and interpreted in terms of a circumstellar disk, heating processes, and minor mass ejections. It is suggested that the transients and ejections in Lambda Eri in terms of small-scale magnetic flaring processes are similar to those on the sun, T Tauri stars, and several other types of magnetically active cool stars. In some classical Be stars, quasi-cycles originate from chaotic knots of magnetic field that periodically drift to the surface, as on the sun, and dissipate through flaring triggered by sudden changes in field topology. 102 refs.

• OSTI ID: 7017903
• Journal Information: Astrophysical Journal, Supplement Series; (USA), Journal Name: Astrophysical Journal, Supplement Series; (USA) Vol. 71; ISSN APJSA; ISSN 0067-0049
• 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
ELEMENTS
FLUIDS
GASES
HEATING
HELIUM
MAGNETIC STARS
MASS TRANSFER
MONITORING
NONMETALS
OSCILLATIONS
RARE GASES
SPECTROSCOPY
STARS
STELLAR ACTIVITY
STELLAR FLARES
VARIABLE STARS