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KATSOVA M.M. , LIVSHITS М.А. Sternberg Astronomical Institute, Moscow State University

KATSOVA M.M. , LIVSHITS М.А. Sternberg Astronomical Institute, Moscow State University IZMIRAN, Troitsk HOW STELLAR FLARE EXPERIENCE CAN HELP IN SOLAR INVESTIGATIONS?. Our SUN. The soft X-ray emission of the late-type stars. - ROSAT, 0.1 – 2.4 keV - The Sun

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KATSOVA M.M. , LIVSHITS М.А. Sternberg Astronomical Institute, Moscow State University

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  1. KATSOVA M.M.,LIVSHITS М.А. Sternberg Astronomical Institute, Moscow State University IZMIRAN, Troitsk HOW STELLAR FLARE EXPERIENCE CAN HELP IN SOLAR INVESTIGATIONS?

  2. Our SUN

  3. The soft X-ray emission of the late-type stars • - ROSAT, • 0.1 – 2.4 keV • - The Sun • at the same spectal range, max,min • Stars from J.Wright et al, 2004 • - Stars of HK ProjectS.Baliunas et al.

  4. The soft X-ray emission of the late-type stars

  5. The chromospheric radiation of the late-type stars

  6. Spots on active late-type stars

  7. Thus, the Sun enters naturally in a family of cyclic stars: the Sun among the active stars with cycles is a hotter star, rotating comparatively faster, while solar spots cover relatively less area than spots on active stars.

  8. Some features : cycles 61 Cyg A Ca II X-Ray ROSAT HRI • Evidence for coronal activity cycles on 61 Cyg A and B • A.Hempelman, J.H.M.M.Schmitt, S.L.Baliunas and R.A.Donahue A & A(2003) V.406, L.39 1992 1998

  9. Some features: cycles and long-term variability of the Sun and some stars HD 1835 Optical continuumV Ca II HD 10476 V Ca II X-rays Ca II Solar irradiance 1975 2000 1965 2000

  10. STELLAR CORONAE: spectra, XMM-Newton M.Güdel, “X-ray astronomy of stellar coronae”. Astron. Astrophys. Rev. 2004

  11. STELLAR CORONAE: ЕМ, Т log T log EM 52 7.0 6.0 50 48 log L(x) 27 29 31 46 M.Güdel. “X-ray astronomy of stellar coronae”. Astron. Astrophys. Rev. 2004 6.0 7.0 log T

  12. IMPULSIVE STELLAR FLARES GAS-DYNAMIC MODELLING: Livshits, Badalyan, Kosovichev and Katsova, 1981, Solar Phys. 73, 269 Katsova, Boiko, Livshits, 1997 A & A , 321, 549

  13. IMPULSIVE FLARES: results and experience Interpretation of simultaneous observations at various spectral ranges Estimation of amount of the evaporated plasma The most reliable method of estimation of the stellar flare area in optics Analysis of secondary processes allows us to conclude about properties of primary energy release

  14. Flares on red dwarf stars M. Guedel “X-ray astronomy of stellar coronae” Astron. Astrophys. Rev. 2004

  15. Flares on red dwarf starsProx Cen

  16. EQ Peg Flare duration in optics – 5 min The EM of flare coronal loops is much more than it was expected from the optical data Katsova, Livshits, J.H.M.M.Schmitt 2002, 2005 “Short powerful flare on EQ Peg as an analog of solar compact flares”

  17. UX Ari I.M.Livshits, M.A.Livshits, R.Pallavicini, 2003, Adv.Space Res. 32(6), 1181

  18. CORONAL HEATING Red dwarfstars - microflaring G-K stars with cycles – plasma heating in coronal loops Active F-Gdwarfs and subgiants–prolonged non-stationary processes in corona

  19. HOW STELLAR FLARE EXPERIENCE CAN HELP IN SOLAR INVESTIGATIONS? CONCLUSIONS • The Sun among active late-type stars with cycles is a typical one. • The soft X-ray emission of stellar coronae allows us to analyse processes in different physical conditions and to distinguish phenomena developing both in strong local and large-scale magnetic fields. It helps to understand how can change the solar corona if heating increases by 3-4 orders of a magnitude and will be realized at small and large spatial structures. • If solar non-stationary phenomena are characterized by energies up to 1032 ergs, so stellar flares give possibility to investigate much more powerful events with total energies up to 1036 ergs. Therefore there is a chance to observe phenomena associated either with a pulse only or with prolonged primary energy release

  20. The End

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