Solar-burst precursors and energy buildup at microwave wavelengths

Technical Report · Wed Jan 01 00:00:00 EST 1986

OSTI ID:6984461

Lang, K R; Willson, R F

High-resolution microwave observations (VLA) of heating and magnetic triggering in coronal loops are summarized. Magnetic changes that precede solar eruptions on time scales of tens of minutes involve primarily emerging coronal loops and the interaction of two or more loops. Thermal cyclotron lines were detected in coronal loops, suggesting the presence of hot current sheets that enhance emission from relatively thin layers of enhanced temperature and constant magnetic field. These current sheets may play a role in the excitation of solar bursts. A filament-associated source with a high brightness temperature and steep radiation spectrum occurs above a region of apparently weak photospheric field. This source might be attributed to currents that enhance coronal magnetic fields. Compact (phi=5 sec) transient sources with lifetimes of 30 to 60 minutes were also detected in regions of apparently weak photospheric field. VLA observations of coronal loops are compared with simultaneous SMM-XRP observations in conclusion.

• Research Organization: Tufts Univ., Medford, MA (USA). Dept. of Physics and Astronomy
• OSTI ID: 6984461
• Report Number(s): AD-A-171925/1/XAB
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
SOLAR ACTIVITY
MICROWAVE RADIATION
SOLAR CORONA
MAGNETIC FIELDS
SOLAR RADIO BURSTS
PRECURSOR
CYCLOTRON RESONANCE
EMISSION SPECTRA
HYDROGEN
MICROWAVE EQUIPMENT
PHOTOSPHERE
PLASMA HEATING
POLARIZATION
ATMOSPHERES
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
HEATING
NONMETALS
RADIATIONS
RADIOWAVE RADIATION
RESONANCE
SOLAR ATMOSPHERE
SPECTRA
STELLAR ATMOSPHERES
STELLAR CORONAE
640104* - Astrophysics & Cosmology- Solar Phenomena