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Flare stars at radio wavelengths
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Lang, Kenneth R. |
| Copyright Year | 1989 |
| Description | The radio emission from dMe flare stars is discussed using Very Large Array and Arecibo observations as examples. Active flare stars emit weak, unpolarized, quiescent radio radiation that may be always present. Although thermal bremsstrahlung and/or thermal gyroresonance radiation account for the slowly-varying, quiescent radio radiation of solar active regions, these processes cannot account for the long-wavelength quiescent radiation observed from nearby dMe flare stars. It has been attributed to nonthermal gyrosynchrotron radiation, but some as yet unexplained mechanism must be continually producing the energetic electrons. Long duration, narrow-band radiation is also emitted from some nearby dMe stars at 20 cm wavelength. Such radiation may be attributed to coherent plasma radiation or to coherent electron-cyclotron masers. Impulsive stellar flares exhibit rapid variations that require radio sources that are smaller than the star in size, and high brightness temperatures greater than 10(exp 15) K that are also explained by coherent radiation processes. Quasi-periodic temporal fluctuations suggest pulsations during some radio flares. Evidence for frequency structure and positive or negative frequency drifts during radio flares from dMe stars is also presented. |
| File Size | 663743 |
| Page Count | 14 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19900012403 |
| Archival Resource Key | ark:/13960/t8jd9rz24 |
| Language | English |
| Publisher Date | 1989-01-01 |
| Access Restriction | Open |
| Subject Keyword | Space Radiation Radio Waves Radio Emission Radio Astronomy Bremsstrahlung Coherent Radiation Very Large Array Vla Radio Stars Brightness Temperature Plasma Radiation Unsteady Flow Flare Stars Stellar Flares Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
