Astrophysics and Space Science

, Volume 95, Issue 2, pp 235-253

First online:

Characteristics of activity energetics of the UV cet-type flare stars

  • R. E. GershbergAffiliated withCrimean Astrophysical Observatory
  • , N. I. ShakhovskayaAffiliated withCrimean Astrophysical Observatory

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A quantitative comparison of energetics of different manifestations of the activity of the UV Cet-type flare stars — sporadic flares, quiet chromospheres and coronae and stellar spots — have been carried out. On the basis of a statistical analysis of about 1800 flares registered for 23 flare stars, the energy spectra of flares have been constructed and time-averaged powers of optical radiation of flares —L flares — have been estimated. By use of spectroscopic observations of 26 flare stars between flares, the total radiation in Balmer lines of quiet chromospheres —L Bal — have been found. On the basis of these data and the soft X-ray observations of 29 flare stars, the mean of the ratiosL flares/L bol,L Bal/L bol andL X /L bol have been found to be equal to (1–2)×10−4. By use of photometric observations for 9 stars, the total starspot radiation deficits —L spots — have been estimated as (4×10−3−6×10−2L bol. Discussions of probable underestimates in the valuesL flares,L Bal,L X , andL spots leads to the conclusion that the total power of non-equilibrium processes that take place in flare star atmospheres is close to the total starspot radiation deficit in these stars.