Titre du document

Solar and stellar flares

Lien vers le document
Nom du Corpus

AstroConcepts

Auteur(s)
  • D. J. Mullan
Affiliation(s)
  • Bartol Research Foundation of The Franklin Institute, 19081, Swarthmore, Penn., U.S.A.
Résumé

Short-lived increases in the brightness of many red dwarfs have been observed for the last 30 yr, and a variety of more or less exotic models have been proposed to account for such flares. Information about flares in the Sun has progressed greatly in recent years as a result of spacecraft experiments, and properties of coronal flare plasma are becoming increasingly better known. In this paper, after briefly reviewing optical, radio and X-ray observations of stellar flares, we show how a simplified model which describes conductive plus radiative cooling of the coronal flare plasma in solar flares has been modified to apply to optical and X-ray stellar flare phenomena. This model reproduces many characteristic features of stellar flares, including the mean UBV colors of flare light, the direction of flare decay in the two-color diagram, precursors, Stillstands, secondary maxima, lack of sensitivity of flare color to flare amplitude, low flux of flare X-rays, distinction between so-called spike flares and slow flares, Balmer jumps of as much as 6–8, and emission line redshifts up to 3000 km s?1. In all probability, therefore, stellar flares involve physical processes which are no more exotic (and no less!) than those in solar flares. Advantages of observing stellar flares include the possibilities of (i) applying optical diagnostics to coronal flare plasma, whereas this is almost impossible in the Sun, and (ii) testing solar flare models in environments which are not generally accessible in the solar atmosphere.

Langue(s) du document
Anglais
Année de publication
1977
Revue

Solar Physics

Éditeur
Springer (journals)
Type de publication
journal
Type de document
review-article
Présence de XML structuré
Non
Version de PDF
1.3
Score de qualité du texte
9.904
Nom du concept
  • BY Draconis stars
Catégories Science-Metrix
  • 1 - natural sciences ; 2 - physics & astronomy ; 3 - astronomy & astrophysics
Catégories Inist
  • 1 - sciences appliquees, technologies et medecines ; 2 - sciences exactes et technologie ; 3 - terre, ocean, espace ; 4 - astronomie
Catégories Scopus
  • 1 - Physical Sciences ; 2 - Earth and Planetary Sciences ; 3 - Space and Planetary Science
  • 1 - Physical Sciences ; 2 - Physics and Astronomy ; 3 - Astronomy and Astrophysics
Catégories WoS
  • 1 - science ; 2 - astronomy & astrophysics
Identifiant ISTEX
B2EBC9DAF8902DA51D1B34656D7BA97FED9F815B
ark:/67375/1BB-F7RQGX72-3
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