Hostname: page-component-76fb5796d-25wd4 Total loading time: 0 Render date: 2024-04-25T08:02:24.964Z Has data issue: false hasContentIssue false
  • English
  • Français

Solar and stellar activity: diagnostics and indices

Published online by Cambridge University Press:  05 July 2012

Philip G. Judge  and
Michael J. Thompson
Philip G. Judge
Affiliation:
High Altitude Observatory, National Center for Atmospheric ResearchPO Box 3000, Boulder CO 80307-3000, USA email: judge@ucar.edu, mjt@ucar.edu
Michael J. Thompson
Affiliation:
High Altitude Observatory, National Center for Atmospheric ResearchPO Box 3000, Boulder CO 80307-3000, USA email: judge@ucar.edu, mjt@ucar.edu
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

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.

Keywords

techniques: photometrictechniques: spectroscopicSun: magnetic fieldsSun: UV radiationSun: chromosphereSun: helioseismologystars: activitystars: evolution
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 7 , Symposium S286: Comparative Magnetic Minima: Characterizing quiet times in the Sun and Stars , October 2011 , pp. 15 - 26
Copyright
Copyright © International Astronomical Union 2012

References

Ayres, T. R. 1997, J. Geophys. Res., 102, 1641CrossRefGoogle Scholar
Ayres, T. R., Judge, P. G., Saar, S. H., & Schmitt, J. H. M. M., 2008, ApJL, 678, L121CrossRefGoogle Scholar
Baliunas, S. & Jastrow, R. 1990, Nature, 348, 520CrossRefGoogle Scholar
Baliunas, S. L., Donahue, R. A., Soon, et al. , 1995, ApJ, 438, 269CrossRefGoogle Scholar
Beer, J., Tobias, S., & Weiss, N. 1998, Solar Phys., 181, 237CrossRefGoogle Scholar
Böhm-Vitense, E. 2007, ApJ, 657, 486CrossRefGoogle Scholar
Brown, B. P., Browning, M. K., Brun, A. S. et al. , 2010, ApJ, 711, 424CrossRefGoogle Scholar
Brown, B. P., Miesch, M. S., Browning, M. K., Brun, A. S., & Toomre, J. 2011, ApJ, 731, 69CrossRefGoogle Scholar
Christensen-Dalsgaard, J. & Thompson, M. J. 2011, in Brummell, N. H., Brun, A. S., Miesch, M. S., & Ponty, Y. (Ed.), IAU Symposium, Vol. 271 of IAU Symposium, p. 32CrossRefGoogle Scholar
Cincunegui, C., Díaz, R. F., & Mauas, P. J. D. 2007, A&A, 461, 1107Google Scholar
Durney, B. R., Mihalas, D., & Robinson, R. D. 1981, PASP, 93, 537CrossRefGoogle Scholar
Fröhlich, C. 2011, Space Sci. Rev., http://dx.doi.org/10.1007/s11214-011-9780-1CrossRefGoogle Scholar
García, R. A., Ceillier, T., Campante, et al. , 2011, ArXiv e-prints, number 1109.6488Google Scholar
Giampapa, M. S., Hall, J. C., Radick, R. R., & Baliunas, S. L. 2006, ApJ, 651, 444CrossRefGoogle Scholar
Hall, J. C. 2008, Living Reviews in Solar Physics, 5, 2CrossRefGoogle Scholar
Hall, J. C., Henry, G. W., Lockwood, G. W. et al. , 2009, Astron. J., 138, 312CrossRefGoogle Scholar
Hall, J. C. & Lockwood, G. W. 2004, ApJL, 614, 942CrossRefGoogle Scholar
Hufbauer, K. 1991, Exploring the sun: solar science since Galileo, Baltimore: JHU pressGoogle Scholar
Judge, P. G. & Saar, S. H. 2007, ApJ, 663, 643CrossRefGoogle Scholar
Judge, P. G., Solomon, S., & Ayres, T. R. 2003, ApJ, 593, 534CrossRefGoogle Scholar
Livingston, W., White, O. R., Wallace, L., & Harvey, J. 2010, Mem. Ast. Sco. It., 81, 643Google Scholar
Lockwood, G. W., Skiff, B. A., Henry, G. W., Henry, et al. , 2007, ApJS, 171, 260CrossRefGoogle Scholar
Metcalfe, T. & 33 co-authors 2012, ApJL, in pressGoogle Scholar
Metcalfe, T. S., Basu, S., Henry, T. J. et al. , 2010, ApJL, 723, L213CrossRefGoogle Scholar
Morgenthaler, A., Petit, P., Aurière, M. et al. , 2010, in Boissier, S., Heydari-Malayeri, M., Samadi, R., & Valls-Gabaud, D. (Ed.), SF2A-2010, 269Google Scholar
Noyes, R. W., Hartmann, L. W., Baliunas, S. L. et al. , 1984, ApJ, 279, 763CrossRefGoogle Scholar
Parker, E. N. 1955, ApJ, 122, 293CrossRefGoogle Scholar
Plachinda, S. I. & Tarasova, T. N. 2000, ApJ, 533, 1016CrossRefGoogle Scholar
Radick, R. R., Lockwood, G. W., Skiff, B. A., & Baliunas, S. L. 1998, ApJS, 118, 239CrossRefGoogle Scholar
Robrade, J., Schmitt, J. H. M. M., & Favata, F. 2005, A&A, 442, 315Google Scholar
Robrade, J., Schmitt, J. H. M. M., & Hempelmann, A. 2007, Mem. Ast. Sco. It., 78, 311Google Scholar
Rottman, G. 2006, Space Sci. Rev., 125, 39CrossRefGoogle Scholar
Saar, S. H. & Brandenburg, A. 1999, ApJ, 524, 295CrossRefGoogle Scholar
Salabert, D., Jiménez-Reyes, S. J., & Tomczyk, S. 2003, A&A, 408, 729Google Scholar
Schmitt, J. H. M. M., 1997, A&A, 318, 215Google Scholar
Schrijver, C. J. & Harvey, K. L. 1994, Solar Phys., 150, 1CrossRefGoogle Scholar
Schrijver, C. J., Livingston, W. C., Woods, T. N., & Mewaldt, R. A. 2011, GRL, 38, 6701CrossRefGoogle Scholar
Schrijver, C. J. & Zwaan, C. 2000, Solar and Stellar Magnetic Activity, Cambridge Univ. Press, Cambridge, UKCrossRefGoogle Scholar
Semel, M. 1989, Astron. Astrophys., 225, 456Google Scholar
Spruit, H. C. 2011, in Miralles, M. P. & Sánchez Almeida, J. (Ed.), The Sun, the Solar Wind, and the Heliosphere, IAGA Special Sopron Book Series, Vol. 4. Berlin: Springer, 39CrossRefGoogle Scholar
Stern, R. A., Alexander, D., & Acton, L. W. 2003, in Brown, A., Harper, G. M., & Ayres, T. R. (Ed.), 12th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, 12, 906Google Scholar
Wilson, O. C. 1968, ApJ, 153, 221CrossRefGoogle Scholar
Wright, J. T. 2004, Astron. J., 128, 1273CrossRefGoogle Scholar