Dynamic spectra of radio bursts from flare stars

Journal Article · Sun Apr 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168613· OSTI ID:6807018

Bastian, T S; Bookbinder, J; Dulk, G A; Davis, M ^[1]

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1. National Radio Astronomy Observatory, Socorro, NM (USA) Joint Institute for Laboratory Astrophysics, Boulder, CO (USA) Smithsonian Astrophysical Observatory, Cambridge, MA (USA) Colorado Univ., Boulder (USA)

The Arecibo 305 m telescope has been used to observe radio bursts from flare stars at 430 and 1415 MHz. Dynamic spectra of the emission with bandwidths of 10 MHz in the former case and 40 MHz in the latter are recorded. For AD Leo, the microwave burst emission was 100 percent right circularly polarized, achieved brightness temperatures near 10 to the 16th K, was generally broadband in character, but was superposed with finite structures in both frequency and time. Quasi-periodic pulsations were clearly present as well as a sudden reduction feature. For YZ CMi, the emission was 100 percent left circularly polarized and was relatively broadband with fine structures. Instabilities driven by anisotropies in the electron distribution, particularly the loss-cone distribution, are considered to account for the coherent radiation. 55 refs.

• OSTI ID: 6807018
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 353; 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
ANISOTROPY
BRIGHTNESS
COHERENT RADIATION
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
EMISSION SPECTRA
FERMIONS
INSTABILITY
LEPTONS
LINE WIDTHS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PLASMA
POLARIZATION
RADIATIONS
RADIOWAVE RADIATION
SPECTRA
STELLAR ACTIVITY
STELLAR FLARES