Abstract
We investigate the magnetic fields and total areas of mid- and low-latitude sunspots based on observations at the Greenwich and Kislovodsk (sunspot areas) and Mount Wilson, Crimean, Pulkovo, Ural, IMIS, Ussuriysk, IZMIRAN, and Shemakha (magnetic fields) observatories. We show that the coefficients in the linear form of the dependence of the logarithm of the total sunspot area S on its maximum magnetic field H change with time. Two distinct populations of sunspots are identified using the twodimensional H–log S occurrence histogram: small and large, separated by the boundaries log S = 1.6 (S = 40 MSH) and H = 2050 G. Analysis of the sunspot magnetic flux also reveals the existence of two lognormally distributed populations with the mean boundary between them Φ = 1021 Mx. At the same time, the positions of the flux occurrence maxima for the populations change on a secular time scale: by factors of 4.5 and 1.15 for small and large sunspots, respectively. We have confirmed that the sunspots form two physically distinct populations and show that the properties of these populations change noticeably with time. This finding is consistent with the hypothesis about the existence of two magnetic field generation zones on the Sun within the framework of a spatially distributed dynamo.
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References
J. M. Beckers and E.H. Schröter, Solar Phys. 10, 384 (1969).
T. J. Bogdan, P. A. Gilman, I. Lerche, and R. Howard, Astrophys. J. 327, 451 (1988).
A. Brandenburg, Astrophys. J. 625, 539 (2005).
R. J. Bray and R. E. Loughhead, Sunspots (Chapman and Hall, London, 1964).
J. W. Broxon, Phys. Rev. 62, 508 (1942).
I.-H. Cho, K.-S. Cho, S.-C. Bong, E.-K. Lim, R.-S. Kim, S. Choi, Y.-H. Kim, and V. Yurchyshyn, Astrophys. J. 811, 49 (2015).
G. E. Hale and S. B. Nicholson, Magnetic Observations of Sunspots, 1917–1924, Papers of the Mt. Wilson Observ., Vol. 5 (Carnegie Inst.,Washington, 1938).
J. Houtgast and A. van Sluiters, Bull. Astron. Instit. Netherl. 10, 325 (1948).
C. Kiess, R. Rezaei, and W. Schmidt, Astron. Astrophys. 565, 52 (2014).
Yu. V. Linnik, Method of Least Squares and Principles of the Theory of Observations (Fizmatlit, Moscow, 1962; Pergamon, Oxford, 1961).
W. Livingston, J. W. Harvey, O. V. Malanushenko, and L. Webster, Solar Phys. 239, 41 (2006).
W. Livingston, M. J. Penn, and L. Svalgaard, Astrophys. J. Lett. 757, L8 (2012).
W. Mattig, Z. Astrophys. 31, 273 (1953).
A. Munoz-Jaramillo, R. R. Senkpeil, J. C. Windmueller, E. C. Amouzou, D.W. Longcope, A. G. Tlatov, Y. A. Nagovitsyn, A. A. Pevtsov, G. A. Chapman, A. M. Cookson, A. R. Yeates, F. T. Watson, L. A. Balmaceda, E. E.DeLuca, and P. C.H. Martens, Astrophys. J. 800, 48 (2015).
Yu. A. Nagovitsyn, V. V. Makarova, E. Yu. Nagovitsyna, Solar Syst. Res. 41, 81 (2007).
Yu. A. Nagovitsyn, A. A. Pevtsov, and W. Livingston, Astrophys. J. Lett. 758, L20 (2012).
Yu. A. Nagovitsyn, K. Georgieva, A. A. Osipova, and A. I. Kuleshova, Geomagn. Aeron. 55, 1081 (2015).
S. B. Nicholson, Astron. Soc. Pacif. 45, 51 (1933).
M. J. Penn and W. Livingston, Astrophys. J. 649, L45 (2006).
A. A. Pevtsov, Y. A. Nagovitsyn, A. G. Tlatov, and A. L. Rybak, Astrophys. J. Lett. 42, L36 (2011).
A. A. Pevtsov, L. Bertello, A. G. Tlatov, A. Kilcik, Y. A. Nagovitsyn, and E. W. Cliver, Solar Phys. 289, 593 (2014).
R. Rezaei, C. Beck, and W. Schmidt, Astron. Astrophys. 541, A60 (2012).
R. Rezaei, C. Beck, A. Lagg, J. M. Borrero, W. Schmidt, and M. Collados, Astron. Astrophys. 578, A43 (2015).
T. S. Ringnes, Astrophys. Norveg. 10, 27 (1965).
T. S. Ringnes and E. Jensen, Astrophys. Norveg. 7, 99 (1960).
T. A. Schad, Solar Phys. 289, 1477 (2014).
O. Steen and P. Maltby, Astrophys. Norveg. 6, 263 (1960).
V. E. Stepanov and S. I. Gopasyuk, Izv. Krymsk. Astrofiz. Observ. 28, 194 (1962).
A. G. Tlatov and A. A. Pevtsov, Solar Phys. 289, 1143 (2014).
K. A. Tlatova, V. V. Vasil’eva, and A. A. Pevtsov, Geomagn. Aeron. 55, 896 (2015).
A. Wittmann, Solar Phys. 36, 29 (1974).
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Original Russian Text © Yu.A. Nagovitsyn, A.A. Pevtsov, A.A. Osipova, A.G. Tlatov, E.V. Miletskii, E.Yu. Nagovitsyna, 2016, published in Pis’ma v Astronomicheskii Zhurnal, 2016, Vol. 42, No. 10, pp. 773–782.
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Nagovitsyn, Y.A., Pevtsov, A.A., Osipova, A.A. et al. Two populations of sunspots and secular variations of their characteristics. Astron. Lett. 42, 703–712 (2016). https://doi.org/10.1134/S1063773716090048
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DOI: https://doi.org/10.1134/S1063773716090048