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Solar and stellar activity: diagnostics and indices

  • Philip G. Judge (a1) and Michael J. Thompson (a1)
Abstract
Abstract

We summarize the fifty-year concerted effort to place the “activity” of the Sun in the context of the stars. As a working definition of solar activity in the context of stars, we adopt those globally–observable variations on time scales below thermal time scales, of ~105 yr for the convection zone. So defined, activity is dominated by magnetic–field evolution, including the 22–year Hale cycle, the typical time it takes for the quasi-periodic reversal in which the global magnetic–field takes place. This is accompanied by sunspot variations with 11 year periods, known since the time of Schwabe, as well as faster variations due to rotation of active regions and flaring. “Diagnostics and indices” are terms given to the indirect signatures of varying magnetic–fields, including the photometric (broad-band) variations associated with the sunspot cycle, and variations of the accompanying heated plasma in higher layers of stellar atmospheres seen at special optical wavelengths, and UV and X-ray wavelengths. Our attention is also focussed on the theme of the Symposium by examining evidence for deep and extended minima of stars, and placing the 70–year long solar Maunder Minimum into a stellar context.

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T. R. Ayres 1997, J. Geophys. Res., 102, 1641

T. R. Ayres , P. G. Judge , S. H. Saar , & J. H. M. M. Schmitt , 2008, ApJL, 678, L121

S. Baliunas & R. Jastrow 1990, Nature, 348, 520

S. L. Baliunas , R. A. Donahue , Soon , 1995, ApJ, 438, 269

J. Beer , S. Tobias , & N. Weiss 1998, Solar Phys., 181, 237

E. Böhm-Vitense 2007, ApJ, 657, 486

B. P. Brown , M. K. Browning , A. S. Brun , 2010, ApJ, 711, 424

B. P. Brown , M. S. Miesch , M. K. Browning , A. S. Brun , & J. Toomre 2011, ApJ, 731, 69

C. Cincunegui , R. F. Díaz , & P. J. D. Mauas 2007, A&A, 461, 1107

B. R. Durney , D. Mihalas , & R. D. Robinson 1981, PASP, 93, 537

M. S. Giampapa , J. C. Hall , R. R. Radick , & S. L. Baliunas 2006, ApJ, 651, 444

J. C. Hall 2008, Living Reviews in Solar Physics, 5, 2

J. C. Hall , G. W. Henry , G. W. Lockwood , 2009, Astron. J., 138, 312

J. C. Hall & G. W. Lockwood 2004, ApJL, 614, 942

P. G. Judge & S. H. Saar 2007, ApJ, 663, 643

P. G. Judge , S. Solomon , & T. R. Ayres 2003, ApJ, 593, 534

G. W. Lockwood , B. A. Skiff , G. W. Henry , Henry , 2007, ApJS, 171, 260

T. S. Metcalfe , S. Basu , T. J. Henry , 2010, ApJL, 723, L213

R. W. Noyes , L. W. Hartmann , S. L. Baliunas , 1984, ApJ, 279, 763

E. N. Parker 1955, ApJ, 122, 293

S. I. Plachinda & T. N. Tarasova 2000, ApJ, 533, 1016

R. R. Radick , G. W. Lockwood , B. A. Skiff , & S. L. Baliunas 1998, ApJS, 118, 239

J. Robrade , J. H. M. M. Schmitt , & F. Favata 2005, A&A, 442, 315

G. Rottman 2006, Space Sci. Rev., 125, 39

S. H. Saar & A. Brandenburg 1999, ApJ, 524, 295

D. Salabert , S. J. Jiménez-Reyes , & S. Tomczyk 2003, A&A, 408, 729

C. J. Schrijver & K. L. Harvey 1994, Solar Phys., 150, 1

C. J. Schrijver , W. C. Livingston , T. N. Woods , & R. A. Mewaldt 2011, GRL, 38, 6701

H. C. Spruit 2011, in M. P. Miralles & J. Sánchez Almeida (Ed.), The Sun, the Solar Wind, and the Heliosphere, IAGA Special Sopron Book Series, Vol. 4. Berlin: Springer, 39

O. C. Wilson 1968, ApJ, 153, 221

J. T. Wright 2004, Astron. J., 128, 1273

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Proceedings of the International Astronomical Union
  • ISSN: 1743-9213
  • EISSN: 1743-9221
  • URL: /core/journals/proceedings-of-the-international-astronomical-union
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