VLA observations of a solar noise storm
The first Very Large Array (VLA) observations of the sun at 92 cm wavelength (328 MHz) are presented. A 3-hr solar noise storm was detected; it consisted of burst-like spikes superimposed on a slowly varying background, and both storm components were 95 + or - 5 percent right-hand circularly polarized. A long duration soft X ray event preceeded the radio radiation by 30 m, suggesting a disturbance moving outwards at a velocity of v = 78 km/s. The 92 cm noise storm was resolved with an angular resolution of 9 sec for time intervals as short as 13 s. During the onset and early phases, the storm consisted of four compact sources, each with an angular diameter of 40 sec, oriented within an elongated source with angular dimensions of 40 sec by 200 sec. During the subsequent hour the most intense emission was located in two 40 sec sources separated by 100 sec. Snapshot maps revealed a persistent elongated source ta successive Peaks, with a scatter in the source position. A systematic position shift of Delta Theta sub I greater than or = 15 sec can be produced by the earth's ionoshere, but these effects can be removed by frequent observations of a nearby calibrator source. The observations confirm previously reported trends for a decrease in source size at higher frequencies, but they suggest a hitherto unresolved complexity in source structure. 18 references.
- Research Organization:
- Tufts Univ., Medford, MA
- OSTI ID:
- 5930520
- Journal Information:
- Astrophys. J.; (United States), Vol. 319
- Country of Publication:
- United States
- Language:
- English
Similar Records
J. VLA (Very Large Array) of a solar noise storm
VLA (Very Large Array) observations of a solar-noise storm
Related Subjects
GENERAL PHYSICS
SUN
RADIOWAVE RADIATION
CALIBRATION
EMISSION
IONOSPHERIC STORMS
MAGNETIC STORMS
RADIO TELESCOPES
SOFT X RADIATION
SOLAR ACTIVITY
ANTENNAS
ELECTRICAL EQUIPMENT
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
EQUIPMENT
IONIZING RADIATIONS
MAIN SEQUENCE STARS
RADIATIONS
RADIO EQUIPMENT
STARS
TELESCOPES
X RADIATION
640104* - Astrophysics & Cosmology- Solar Phenomena
640201 - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena