Abstract
The physical state of the photosphere 1 h 50 min before a C1 solar flare on May 24, 2012, was studied. The spectropolarimetric data from the French-Italian THEMIS telescope (Tenerife Island, Spain) were used. The modeling was carried out through the inversion method using SIR [B. Ruiz Cobo and J. C. del Toro Iniesta, Astrophys. J. 398, 375–385 (1992)] code. Height distributions of temperature, magnetic field strength, and line-of-sight velocity were obtained. Nine semiempirical models of the photosphere were constructed. Each model has a two-component (a magnetic field component and nonmagnetic surroundings) structure. According to the obtained models, the magnetic field parameters and thermodynamic parameters did change significantly in the course of observations that lasted for 8 min. The models contain layers with increased and decreased temperature values. The magnetic field strength in these models varied, on average, from 0.2 T (lower photospheric layers) to 0.13 T (upper layers). The line-of-sight velocities did not exceed 2 km/s in lower and middle photospheric layers and rose to 5–6 km/s in the upper layers. The differences in the physical state and its changes occurring at different sites within the active region prior to the flare were revealed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
K. V. Alikaeva, N. N. Kondrashova, T. I. Redyuk, and E. G. Rudnikova, “Lower photosphere in solar active regions prior to flares and without flares. I. Fraunhofer spectrum,” Kinematika Fiz. Nebesnykh Tel 9(1), 24–36 (1993).
K. V. Alikaeva, N. N. Kondrashova, T. I. Redyuk, and E. G. Rudnikova, “On the nature of temporal changes in the physical state of the photospheric layers prior to flares,” Izv. Krym. Astrofiz. Obs. 92, 52–56 (1995).
K. V. Alikaeva and S. N. Chornogor, “Preflare chromospheric and photospheric line-of-sight velocities,” in Multi-Wavelength Investigations of Solar Activity: Proceedings of the International Astronomical Union Symposium 223, Ed. by A. V. Stepanov, E. E. Benevolenskaya, and A. G. Kosovichev (Cambridge Univ. Press, Cambridge, 2004), pp. 227–228.
K. V. Alikaeva, N. N. Kondrashova, T. I. Redyuk, and E. G. Rudnikova, “Lower photosphere in solar active regions prior to flares and without flares. II. Physical conditions,” Kinematics Phys. Celestial Bodies 9(2), 50–60 (1993).
A. Ambastha, “Signatures of large flares on photospheric magnetic and velocity fields,” in Second UN/NASA Workshop on International Heliophysical Year and Basic Space Science. Proceedings of the Conference Held 27 November — 1 December, 2006, at Indian Institute of Astrophysics, Bangalore. Book of Abstracts, p. 26.
J. M. Beckers, A Table of Zeeman Multiplets (Sacramento Peak Obs. and Air Force Cambridge Res. Lab., Bedford, 1969).
L. R. Bellot Rubio, B. Ruiz Cobo, and M. Collados, “Structure of plage flux tubes from the inversion of Stokes spectra. I. Spatially averaged Stokes I and V profiles,” Astrophys. J. 535, 489–500 (2000).
G. Cauzzi, A. Falchi, R. Falciani, and L. A. Smaldone, “Coordinated observations of solar activity phenomena. II. The velocity field pattern in an elementary flare,” Astron. Astrophys. 306, 625–637 (1996).
S. N. Chornogor and N. N. Kondrashova, “Physical state of the photosphere at the onset phase of a two-ribbon solar flare,” Sol. Phys. 250, 303–314 (2008).
A. Falchi, J. Qiu, and G. Cauzzi, “Chromospheric evidence for magnetic reconnection,” Astron. Astrophys. 328, 371–380 (1997).
K. L. Harvey and J. W. Harvey, “A study of the magnetic and velocity fields in an active region,” Sol. Phys. 47, 233–246 (1976).
J. Heyvaerts, E. R. Priest, and D. M. Rust, “An emerging flux model for the solar flare phenomenon,” Astrophys. J. 216, 123–137 (1977).
T. T. Ishii, H. Kurokawa, and T. T. Takeuchi, “Emergence of a twisted magnetic-flux bundle as a source of strong flare activity,” Astrophys. J. 499, 898–904 (1998).
T. T. Ishii, H. Kurokawa, and T. T. Takeuchi, “Emergence of twisted magnetic-flux bundles and flare activity in a large active region, NOAA 4201,” Publ. Astron. Soc. Japan. 52, 337–354 (2000).
J. Kim, H. S. Jun, S. Lee, et al., “A rapid change in magnetic connectivity observed before filament eruption and its associated flare,” Astrophys. J., Lett. 547, L85–L88 (2001).
N. N. Kondrashova, “Pre-flare changes in the Fraunhofer lines,” Kinematics Phys. Celestial Bodies 11(2), 33–39 (1995).
N. Meunier and A. Kosovichev, “Fast photospheric flows and magnetic fields in a flaring active region,” Astron. Astrophys. 412, 541–553 (2003).
C. E. Moore, M. G. J. Minnaert, and J. Houtgast, The Solar Spectrum 2935 (US Government Printing Office, Washington, D.C., 1966).
S. A. Murray, D. S. Bloomfield, and P. T. Gallagher, “The evolution of sunspot magnetic fields associated with a solar flare,” Sol. Phys. 277, 45–57 (2012).
B. Ruiz Cobo and J. C. del Toro Iniesta, “Inversion of Stokes profiles,” Astrophys. J. 398, 375–385 (1992).
D. M. Rust, “Analysis of the August 7, 1972 white light flare: changes in the magnetic and velocity fields,” Sol. Phys. 33, 205–212 (1973).
V. S. Titov and P. Démoulin, “Basic topology of twisted magnetic configurations in solar flares,” Astron. Astrophys. 351, 707–720 (1999).
Y. Uchida and K. Shibata, “A magnetodynamic mechanism for the heating of emerging magnetic flux tubes and loop flares,” Sol. Phys. 116, 291–307 (1988).
H. Wang, J. Qiu, J. Jing, et al., “Evidence of rapid flux emergence associated with the M8.7 flare on 2002 July 26,” Astrophys. J. 605, 931–937 (2004).
Author information
Authors and Affiliations
Additional information
Original Russian Text © E.S. Andriiets, N.N. Kondrashova, 2014, published in Kinematika i Fizika Nebesnykh Tel, 2014, Vol. 30, No. 1, pp. 50–60.
About this article
Cite this article
Andriiets, E.S., Kondrashova, N.N. Preflare changes in the solar photosphere observed using the THEMIS telescope. Kinemat. Phys. Celest. Bodies 30, 32–39 (2014). https://doi.org/10.3103/S0884591314010024
Received:
Published:
Issue Date:
DOI: https://doi.org/10.3103/S0884591314010024