On chromospheric variations modeling for main-sequence stars of G and K spectral classes

E. A Bruevich
DOI: 10.4236/ns.2011.38087                

Abstract

We present a method of 13 late-type main-sequence stars chromospheric flux observation data calculations. These Sun-like stars have well-determined cyclic flux variations similar to the 11-year solar activity cycle. Our flux prediction is based on chromospheric HK emission time series measurements from the Mount Wilson Observatory and comparable solar data. We show that solar three - component modeling explains well the stellar observations. We find that the 10 - 20% of K - stars disc’s surfaces are occupied by bright active regions.

Keywords

The Sun; Late-Type Stars; Chromospheric Emission

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Baliunas, S.L., Donahue, R.A. and Soon, W. (1995) Chromospheric variations in main-sequence stars, Astrophysical Journal, 438, 269-280. doi.org/10.1086/175072
[2]	Lockwood, G.W., Skif, B.A., Radick, R.R., Baliunas, S.L., Donahue, R.A. and Soon, W. (2007) Patterns of photome- tric and chromospheric variations among sun-like stars: a 20-year perspectives, Astrophysical Journal Supplied, 171, 260-320. doi.org/10.1086/516752
[3]	Vernazza, J.E., Avrett, E.H. and Loeser, R. (1981) Structure of chromosphere, Astrophysical Journal Supplied, 45, 635-690. doi.org/10.1086/190731
[4]	Schrijver, C.J., Zwaan, C., Maxon, C.W. and Noyes, R.W. (1985) Astronomy and Astrophysics, 149, 123-132.
[5]	Lean, J.L. and Scumanich A. (1983) Three - structured model of solar chromosphere based on the NIMBUS-7 satellite observations, Journal of Geophysical Research, A88, 5751-5765. doi.org/10.1029/JA088iA07p05751
[6]	Cook, J.W., Brueckner, G.E. and Van Hoosier, M.E., (1980) The center-to limb behavior of solar active regions at ultraviolet, Journal of Geophysical Research, A85, 2257-2266. doi.org/10.1029/JA085iA05p02257
[7]	Borovik, V.N., Livshitz, M.A. and Medar, V.G. (1997) The structure of solar atmosphere, Astronomy Reports, 41, 836-845.
[8]	Bruevich, E.A., (1997) On chromospheric activity of sun-like stars, Moscow University Physical Bull, Moscow, 48-54.