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Flare induced penumbra formation in the sunspot of NOAA 10838

Published online by Cambridge University Press:  26 August 2011

Sreejith Padinhatteeri  and
Sankarasubramanian K.
Sreejith Padinhatteeri
Affiliation:
Space Astronomy Group, ISRO Satellite Centre, Bangalore, India - 560017 email: sreejith.p@gmail.com, sankark@isac.gov.in Dept. of Physics, University of Calicut, Kerala, India.
Sankarasubramanian K.
Affiliation:
Space Astronomy Group, ISRO Satellite Centre, Bangalore, India - 560017 email: sreejith.p@gmail.com, sankark@isac.gov.in
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Abstract

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We have observed formation of penumbrae on a pore in the active region NOAA10838 using Dunn Solar Telescope at NSO, Sunpot, USA. Simultaneous observations using different instruments (DLSP, UBF, Gband and CaK) provide us with vector magnetic field at photosphere, intensity images and Doppler velocity at different heights from photosphere to chromosphere. Results from our analysis of this particular data-set suggests that penumbrae are formed as a result of relaxation of magnetic field due to a flare happening at the same time. Images in Hα show the flare (C 2.9 as per GOES) and vector magnetic fields show a re-orientation and reduction in the global α value (a measure of twist). We feel such relaxation of loop structures due to reconnections or flare could be one of the way by which field lines fall back to the photosphere to form penumbrae.

Keywords

Sunspotpenumbraflare
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 6 , Symposium S273: The Physics of Sun and Star Spots , August 2010 , pp. 303 - 307
Copyright
Copyright © International Astronomical Union 2011

References

Beckers, J. M., Dickson, L., & Joyce, R. S., 1975, AFCRL Report No. AFCRL-TR-75-0090, A ir Force Cambridge Research Laboratory, Massachusetts.Google Scholar
Bray, R. J. & Loughhead, R. E. 1964, Sunspots (The International Astrophysics Series, London: Chapman Hall, 1964)Google Scholar
Brummell, N. H., Tobias, S. M., Thomas, J. H., & Weiss, N. O. 2008, ApJ, 686, 1454CrossRefGoogle Scholar
Leka, K. D. & Skumanich, A. 1998, ApJ, 507, 454Google Scholar
Rimmele, T. 2008, ApJ, 672, 684CrossRefGoogle Scholar
Rimmele, T. R., Richards, K., Hegwer, S., et al. 2004, in SPIE Conf. Ser., eds. Fineschi, S. & Gummin, M. A., SPIE Conf. Ser., 5171, 179Google Scholar
Sankarasubramanian, K., Lites, B., Gullixson, C., et al. 2006, in ASP Conf. Ser., eds. Casini, R. & Lites, B. W., ASP Conf. Ser., 358, 201Google Scholar
Schlichenmaier, R., Rezaei, R., González, N. B., & Waldmann, T. A. 2010, A&A, 512, L1Google Scholar
Smart, W. M. & Green, R. M. 1977, Textbook on Spherical Astronomy, (Cambidge University Press, Cambidge, 1977)CrossRefGoogle Scholar
Solanki, S. K. 2003, A&AR, 11, 153Google Scholar
Tiwari, S. K., Venkatakrishnan, P., Gosain, S., & Joshi, J. 2009, ApJ, 700, 199Google Scholar
Yang, G., Xu, Y., Wang, H., & Denker, C. 2003, ApJ, 597, 1190CrossRefGoogle Scholar