Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-24T12:59:05.805Z Has data issue: false hasContentIssue false

GREGOR observations of a small flare above a sunspot

Published online by Cambridge University Press:  09 September 2016

M. Sobotka
Affiliation:
Astronomical Institute of the Czech Academy of Sciences, Fričova 298, 25165 Ondřejov, Czech Republic email: [email protected]
J. Dudík
Affiliation:
Astronomical Institute of the Czech Academy of Sciences, Fričova 298, 25165 Ondřejov, Czech Republic email: [email protected]
C. Denker
Affiliation:
Leibniz Institute for Astrophysics Potsdam, An der Sternwarte 16, 14482 potsdam, Germany
H. Balthasar
Affiliation:
Leibniz Institute for Astrophysics Potsdam, An der Sternwarte 16, 14482 potsdam, Germany
J. Jurčák
Affiliation:
Astronomical Institute of the Czech Academy of Sciences, Fričova 298, 25165 Ondřejov, Czech Republic email: [email protected]
W. Liu
Affiliation:
Astronomical Institute of the Czech Academy of Sciences, Fričova 298, 25165 Ondřejov, Czech Republic email: [email protected]
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.

A small flare ribbon above a sunspot umbra in active region 12205 was observed on November 7, 2014, at 12:00 UT in the blue imaging channel of the 1.5-m GREGOR telescope, using a 0.1 nm Ca II H interference filter. Context observations from SDO/AIA, Hinode/SOT, and IRIS show that the ribbon is a part of a larger one that extends through the neighboring positive polarities and also participates in several other flares within the active region. A 140 second long time series of Ca II H images was reconstructed by means of the Multi-Frame Blind Deconvolution method, giving the respective spatial and temporal resolutions of 0”.1 and 1 s. Light curves and horizontal velocities of small-scale bright knots in the observed flare ribbon were measured. Some knots are stationary but three move along the ribbon with speeds of 7–11 km s−1. Two of them move in the opposite direction and exhibit highly correlated intensity changes, providing evidence for the presence of slipping reconnection at small spatial scales.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2016 

References

Aulanier, G., Janvier, M., & Schmieder, B. 2012, Astron. Astrophys., 543, A110 CrossRefGoogle Scholar
Aulanier, G., Pariat, E., Démoulin, P., & DeVore, C. R. 2006, Solar Phys., 238, 347 CrossRefGoogle Scholar
Berkefeld, T., Schmidt, D., & Soltau, D., et al. 2012, Astronomische Nachrichten, 333, 863 CrossRefGoogle Scholar
Boerner, P., Edwards, C., & Lemen, J., et al. 2012, Solar Phys., 275, 41 Google Scholar
De Pontieu, B., Title, A. M., & Lemen, J. R., et al. 2014, Solar Phys., 289, 2733 Google Scholar
Démoulin, P., Bagala, L. G., & Mandrini, C. H., et al. 1997, Astron. Astrophys., 325, 305 Google Scholar
Dudík, J., Janvier, M., Aulanier, G., et al. 2014, Astrophys. J., 784, 144 Google Scholar
Fletcher, L., Dennis, B. R., & Hudson, H. S., et al. 2011, Space Sci. Rev., 159, 19 Google Scholar
Janvier, M., Aulanier, G., Pariat, E., & Démoulin, P. 2013, Astron. Astrophys., 555, A77 Google Scholar
Lemen, J. R., Title, A. M., & Akin, D. J., et al. 2012, Solar Phys., 275, 17 CrossRefGoogle Scholar
Li, T. & Zhang, J. 2015, Astrophys. J., 804, L8 Google Scholar
November, L. J. & Simon, G. W. 1988, Astrophys. J., 333, 427 Google Scholar
Pesnell, W. D., Thompson, B. J., & Chamberlin, P. C. 2012, Solar Phys., 275, 3 CrossRefGoogle Scholar
Priest, E. 2014, Magnetohydrodynamics of the Sun (Cambridge: Cambridge University Press)CrossRefGoogle Scholar
Priest, E. & Forbes, T. 2000, Magnetic Reconnection (Cambridge: Cambridge University Press)CrossRefGoogle Scholar
Priest, E. R. & Démoulin, P. 1995, J. Geophys. Res., 1002, 23443 Google Scholar
Puschmann, K. G., Denker, C., & Kneer, F., et al. 2012, Astronomische Nachrichten, 333, 880 CrossRefGoogle Scholar
Schmidt, W., von der Lühe, O., Volkmer, R., et al. 2012, Astronomische Nachrichten, 333, 796 Google Scholar
van Noort, M., Rouppe van der Voort, L., & Löfdahl, M. G. 2005, Solar Phys., 228, 191 Google Scholar
Tsuneta, S., Ichimoto, K., & Katsukawa, Y., et al. 2008, Solar Phys., 249, 167 CrossRefGoogle Scholar