Solar Physics

, Volume 291, Issue 7, pp 1939–1955 | Cite as

Kinematics and Magnetic Properties of a Light Bridge in a Decaying Sunspot

  • M. FalcoEmail author
  • J. M. Borrero
  • S. L. Guglielmino
  • P. Romano
  • F. Zuccarello
  • S. Criscuoli
  • A. Cristaldi
  • I. Ermolli
  • S. Jafarzadeh
  • L. Rouppe van der Voort


We present the results obtained by analysing high spatial and spectral resolution data of the solar photosphere acquired by the CRisp Imaging SpectroPolarimeter at the Swedish Solar Telescope on 6 August 2011 of a large sunspot with a light bridge (LB) observed in NOAA AR 11263. These data are complemented by simultaneous Hinode Spectropolarimeter (SP) observation in the Fe I 630.15 nm and 630.25 nm lines. The continuum intensity map shows a discontinuity in the radial distribution of the penumbral filaments in correspondence with the LB, which shows a dark lane (\({\approx}\,0.3''\) wide and \({\approx}\,8.0''\) long) along its main axis. The available data were inverted with the Stokes Inversion based on Response functions (SIR) code and physical parameters maps were obtained. The line-of-sight (LOS) velocity of the plasma along the LB derived from the Doppler effect shows motions towards and away from the observer up to \(0.6~\mbox{km}\,\mbox{s}^{-1}\) that are lower in value than the LOS velocities observed in the neighbouring penumbral filaments. The noteworthy result is that we find motions towards the observer of up to \(0.6~\mbox{km}\,\mbox{s}^{-1}\) in the dark lane where the LB is located between two umbral cores, while the LOS velocity motion towards the observer is strongly reduced where the LB is located between an umbral core at one side and penumbral filaments on the other side. Statistically, the LOS velocities correspond to upflows or downflows, and comparing these results with Hinode/SP data, we conclude that the surrounding magnetic field configuration (whether more or less inclined) could have a role in maintaining the conditions for the process of plasma pile-up along the dark lane. The results obtained from our study support and confirm outcomes of recent magneto-hydrodynamic simulations showing upflows along the main axis of an LB.


Sun: photosphere Sun: magnetic fields Sun: sunspots Sun: high resolution observations 



We are grateful to the University of Catania for providing the funds necessary to carry out the Observational Campaign in La Palma. The 1-m Swedish Solar Telescope is operated on the island of La Palma by the Institute for Solar Physics (ISP) of Stockholm University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. Hinode is a Japanese mission developed and launched by ISAS/JAXA, with NAOJ as domestic partner and NASA and STFC (UK) as international partners. It is operated by these agencies in co-operation with ESA and NSC (Norway). The HMI/SDO data used in this paper are courtesy of NASA/SDO and the HMI science team. Use of NASA’s Astrophysical Data System is gratefully acknowledged. We are grateful to Dr. Rolf Schlichenmaier for the useful discussions and helpful suggestions. This research has received funding from the EC 7th Framework Programme FP7/2007-2013 under the grant agreement eHEROES (project n. 284461). We are grateful to the SOLARNET project for providing the grant for the Young Researches Mobility (project n. 312495). This work was also supported by the Instituto Nazionale di Astrofisica (PRIN INAF 2014), and by the University of Catania (PRIN MIUR 2012).


  1. Asai, A., Ishii, T.T., Kurokawa, H.: 2001, Plasma ejections from a light bridge in a sunspot umbra. Astrophys. J. 555, L65.  DOI. ADS. ADSCrossRefGoogle Scholar
  2. Balthasar, H., Schmidt, W.: 1993, Polarimetry and spectroscopy of a simple sunspot. 2: On the height and temperature dependence of the magnetic field. Astron. Astrophys. 279, 243. ADS. ADSGoogle Scholar
  3. Berger, T.E., Berdyugina, S.V.: 2003, The observation of sunspot light-bridge structure and dynamics. Astrophys. J. 589, L117.  DOI. ADS. ADSCrossRefGoogle Scholar
  4. Borrero, J.M., Ichimoto, K.: 2011, Magnetic structure of sunspots. Living Rev. Solar Phys. 8, 4.  DOI. ADS. ADSCrossRefGoogle Scholar
  5. Borrero, J.M., Tomczyk, S., Kubo, M., Socas-Navarro, H., Schou, J., Couvidat, S., Bogart, R.: 2011, VFISV: Very Fast Inversion of the Stokes Vector for the helioseismic and magnetic imager. Solar Phys. 273, 267.  DOI. ADS. ADSCrossRefGoogle Scholar
  6. Collados, M., Martinez Pillet, V., Ruiz Cobo, B., del Toro Iniesta, J.C., Vazquez, M.: 1994, Observed differences between large and small sunspots. Astron. Astrophys. 291, 622. ADS. ADSGoogle Scholar
  7. Cowling, T.G.: 1957, Magnetohydrodynamics, Interscience Publishers, Inc., New York. zbMATHGoogle Scholar
  8. Cristaldi, A., Guglielmino, S.L., Zuccarello, F., Romano, P., Falco, M., Rouppe van der Voort, L., de la Cruz Rodríguez, J., Ermolli, I., Criscuoli, S.: 2014, Dynamic properties along the neutral line of a delta spot inferred from high-resolution observations. Astrophys. J. 789, 162.  DOI. ADS. ADSCrossRefGoogle Scholar
  9. de la Cruz Rodríguez, J., Löfdahl, M.G., Sütterlin, P., Hillberg, T., Rouppe van der Voort, L.: 2015, CRISPRED: A data pipeline for the CRISP imaging spectropolarimeter. Astron. Astrophys. 573, A40.  DOI. ADS. ADSCrossRefGoogle Scholar
  10. del Toro Iniesta, J.C., Tarbell, T.D., Ruiz Cobo, B.: 1994, On the temperature and velocity through the photosphere of a sunspot penumbra. Astrophys. J. 436, 400.  DOI. ADS. ADSCrossRefGoogle Scholar
  11. Georgoulis, M.K.: 2005, A new technique for a routine azimuth disambiguation of solar vector magnetograms. Astrophys. J. 629, L69.  DOI. ADS. ADSCrossRefGoogle Scholar
  12. Giordano, S., Berrilli, F., Del Moro, D., Penza, V.: 2008, The photospheric structure of a solar pore with light bridge. Astron. Astrophys. 489, 747.  DOI. ADS. ADSCrossRefGoogle Scholar
  13. Hirzberger, J., Bonet, J.A., Sobotka, M., Vázquez, M., Hanslmeier, A.: 2002, Fine structure and dynamics in a light bridge inside a solar pore. Astron. Astrophys. 383, 275.  DOI. ADS. ADSCrossRefGoogle Scholar
  14. Jurčák, J., Martínez Pillet, V., Sobotka, M.: 2006, The magnetic canopy above light bridges. Astron. Astrophys. 453, 1079.  DOI. ADS. ADSCrossRefGoogle Scholar
  15. Jurčák, J., Sobotka, M., Martínez Pillet, V.: 2005, The magnetic configuration in light bridges. In: The Dynamic Sun: Challenges for Theory and Observations, ESA Special Publication 600, 8.1. ADS. Google Scholar
  16. Katsukawa, Y., Yokoyama, T., Berger, T.E., Ichimoto, K., Kubo, M., Lites, B., Nagata, S., Shimizu, T., Shine, R.A., Suematsu, Y., Tarbell, T.D., Title, A.M., Tsuneta, S.: 2007, Formation process of a light bridge revealed with the Hinode solar optical telescope. Publ. Astron. Soc. Japan 59, S577.  DOI. ADS. ADSCrossRefGoogle Scholar
  17. Kosugi, T., Matsuzaki, K., Sakao, T., Shimizu, T., Sone, Y., Tachikawa, S., Hashimoto, T., Minesugi, K., Ohnishi, A., Yamada, T., Tsuneta, S., Hara, H., Ichimoto, K., Suematsu, Y., Shimojo, M., Watanabe, T., Shimada, S., Davis, J.M., Hill, L.D., Owens, J.K., Title, A.M., Culhane, J.L., Harra, L.K., Doschek, G.A., Golub, L.: 2007, The Hinode (Solar-B) mission: An overview. Solar Phys. 243, 3.  DOI. ADS. ADSCrossRefGoogle Scholar
  18. Leka, K.D.: 1997, The vector magnetic fields and thermodynamics of sunspot light bridges: The case for field-free disruptions in sunspots. Astrophys. J. 484, 900. ADS. ADSCrossRefGoogle Scholar
  19. Lites, B.W., Bida, T.A., Johannesson, A., Scharmer, G.B.: 1991, High-resolution spectra of solar magnetic features. II – Magnetic fields of umbral brightenings. Astrophys. J. 373, 683.  DOI. ADS. ADSCrossRefGoogle Scholar
  20. Lites, B.W., Scharmer, G.B., Berger, T.E., Title, A.M.: 2004, Three-dimensional structure of the active region photosphere as revealed by high angular resolution. Solar Phys. 221, 65.  DOI. ADS. ADSCrossRefGoogle Scholar
  21. Lites, B.W., Akin, D.L., Card, G., Cruz, T., Duncan, D.W., Edwards, C.G., Elmore, D.F., Hoffmann, C., Katsukawa, Y., Katz, N., Kubo, M., Ichimoto, K., Shimizu, T., Shine, R.A., Streander, K.V., Suematsu, A., Tarbell, T.D., Title, A.M., Tsuneta, S.: 2013, The Hinode spectro-polarimeter. Solar Phys. 283, 579.  DOI. ADS. ADSCrossRefGoogle Scholar
  22. Lites, B., Casini, R., Garcia, J., Socas-Navarro, H.: 2007, A suite of community tools for spectro-polarimetric analysis. Mem. Soc. Astron. Ital. 78, 148. ADS. ADSGoogle Scholar
  23. Louis, R.E., Beck, C., Ichimoto, K.: 2014, Small-scale chromospheric jets above a sunspot light bridge. Astron. Astrophys. 567, A96.  DOI. ADS. ADSCrossRefGoogle Scholar
  24. Markwardt, C.B.: 2009, Non-linear least-squares fitting in IDL with MPFIT. In: Bohlender, D.A., Durand, D., Dowler, P. (eds.) Astronomical Data Analysis Software and Systems XVIII, Astronomical Society of the Pacific Conference Series 411, 251. ADS. Google Scholar
  25. Nordlund, Å., Scharmer, G.B.: 2010, Convection and the origin of Evershed flows. Astrophys. Space Sci. Proc. 19, 243.  DOI. ADS. ADSCrossRefGoogle Scholar
  26. Parker, E.N.: 1979a, Sunspots and the physics of magnetic flux tubes. I – The general nature of the sunspot. II – Aerodynamic drag. Astrophys. J. 230, 905.  DOI. ADS. ADSCrossRefGoogle Scholar
  27. Parker, E.N.: 1979b, Sunspots and the physics of magnetic flux tubes. II. Aerodynamic drag. Astrophys. J. 230, 914. ADS. ADSCrossRefGoogle Scholar
  28. Parker, E.N.: 1979c, Sunspots and the physics of magnetic flux tubes. III – Aerodynamic lift. Astrophys. J. 231, 250.  DOI. ADS. ADSCrossRefGoogle Scholar
  29. Pesnell, W.D., Thompson, B.J., Chamberlin, P.C.: 2012, The Solar Dynamics Observatory (SDO). Solar Phys. 275, 3.  DOI. ADS. ADSCrossRefGoogle Scholar
  30. Rempel, M., Schlichenmaier, R.: 2011, Sunspot modeling: From simplified models to radiative MHD simulations. Living Rev. Solar Phys. 8, 3.  DOI. ADS. ADSCrossRefGoogle Scholar
  31. Rimmele, T.: 2008, On the relation between umbral dots, dark-cored filaments, and light bridges. Astrophys. J. 672, 684.  DOI. ADS. ADSCrossRefGoogle Scholar
  32. Rimmele, T.R.: 1997, Evidence for magnetoconvection in a sunspot light bridge. Astrophys. J. 490, 458. ADS. ADSCrossRefGoogle Scholar
  33. Rouppe van der Voort, L., Bellot Rubio, L.R., Ortiz, A.: 2010, Upflows in the central dark lane of sunspot light bridges. Astrophys. J. 718, L78.  DOI. ADS. ADSCrossRefGoogle Scholar
  34. Ruiz Cobo, B., del Toro Iniesta, J.C.: 1992, Inversion of Stokes profiles. Astrophys. J. 398, 375.  DOI. ADS. ADSCrossRefGoogle Scholar
  35. Scharmer, G.B., Bjelksjo, K., Korhonen, T.K., Lindberg, B., Petterson, B.: 2003, The 1-meter Swedish solar telescope. In: Keil, S.L., Avakyan, S.V. (eds.) Innovative Telescopes and Instrumentation for Solar Astrophysics, Proc. SPIE 4853, 341. ADS. CrossRefGoogle Scholar
  36. Scharmer, G.B., Narayan, G., Hillberg, T., de la Cruz Rodriguez, J., Löfdahl, M.G., Kiselman, D., Sütterlin, P., van Noort, M., Lagg, A.: 2008, CRISP spectropolarimetric imaging of penumbral fine structure. Astrophys. J. 689, L69.  DOI. ADS. ADSCrossRefGoogle Scholar
  37. Scherrer, P.H., Schou, J., Bush, R.I., Kosovichev, A.G., Bogart, R.S., Hoeksema, J.T., Liu, Y., Duvall, T.L., Zhao, J., Title, A.M., Schrijver, C.J., Tarbell, T.D., Tomczyk, S.: 2012, The Helioseismic and Magnetic Imager (HMI) Investigation for the Solar Dynamics Observatory (SDO). Solar Phys. 275, 207.  DOI. ADS. ADSCrossRefGoogle Scholar
  38. Schnerr, R.S., de La Cruz Rodríguez, J., van Noort, M.: 2011, Stokes imaging polarimetry using image restoration: A calibration strategy for Fabry–Pérot based instruments. Astron. Astrophys. 534, A45.  DOI. ADS. ADSCrossRefGoogle Scholar
  39. Schüssler, M., Vögler, A.: 2006, Magnetoconvection in a sunspot umbra. Astrophys. J. 641, L73.  DOI. ADS. ADSCrossRefGoogle Scholar
  40. Shimizu, T.: 2011, Long-term evolution of magnetic and dynamical properties in a sunspot light bridge. Astrophys. J. 738, 83.  DOI. ADS. ADSCrossRefGoogle Scholar
  41. Shimizu, T., Katsukawa, Y., Kubo, M., Lites, B.W., Ichimoto, K., Suematsu, Y., Tsuneta, S., Nagata, S., Shine, R.A., Tarbell, T.D.: 2009, Hinode observation of the magnetic fields in a sunspot light bridge accompanied by long-lasting chromospheric plasma ejections. Astrophys. J. 696, L66.  DOI. ADS. ADSCrossRefGoogle Scholar
  42. Sobotka, M., Bonet, J.A., Vazquez, M.: 1994, A high-resolution study of the structure of sunspot light bridges and abnormal granulation. Astrophys. J. 426, 404.  DOI. ADS. ADSCrossRefGoogle Scholar
  43. Spruit, H.C., Scharmer, G.B.: 2006, Fine structure, magnetic field and heating of sunspot penumbrae. Astron. Astrophys. 447, 343.  DOI. ADS. ADSCrossRefGoogle Scholar
  44. Thomas, J.H., Weiss, N.O.: 2004, Fine structure in sunspots. Annu. Rev. Astron. Astrophys. 42, 517.  DOI. ADS. ADSCrossRefGoogle Scholar
  45. Toriumi, S., Katsukawa, Y., Cheung, M.C.M.: 2015, Light bridge in a developing active region. I. Observation of light bridge and its dynamic activity phenomena. Astrophys. J. 811, 137.  DOI. ADS. ADSCrossRefGoogle Scholar
  46. Tsuneta, S., Ichimoto, K., Katsukawa, Y., Nagata, S., Otsubo, M., Shimizu, T., Suematsu, Y., Nakagiri, M., Noguchi, M., Tarbell, T., Title, A., Shine, R., Rosenberg, W., Hoffmann, C., Jurcevich, B., Kushner, G., Levay, M., Lites, B., Elmore, D., Matsushita, T., Kawaguchi, N., Saito, H., Mikami, I., Hill, L.D., Owens, J.K.: 2008, The solar optical telescope for the Hinode mission: An overview. Solar Phys. 249, 167.  DOI. ADS. ADSCrossRefGoogle Scholar
  47. van Noort, M., Rouppe van der Voort, L., Löfdahl, M.G.: 2005, Solar image restoration by use of multi-frame blind de-convolution with multiple objects and phase diversity. Solar Phys. 228, 191.  DOI. ADS. ADSCrossRefGoogle Scholar
  48. Vazquez, M.: 1973, A morphological study of the light-bridges in sunspots. Solar Phys. 31, 377.  DOI. ADS. ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  • M. Falco
    • 1
    • 5
    Email author
  • J. M. Borrero
    • 2
  • S. L. Guglielmino
    • 1
  • P. Romano
    • 3
  • F. Zuccarello
    • 1
  • S. Criscuoli
    • 4
  • A. Cristaldi
    • 5
  • I. Ermolli
    • 5
  • S. Jafarzadeh
    • 6
  • L. Rouppe van der Voort
    • 6
  1. 1.Dipartimento di Fisica e Astronomia – Sezione AstrofisicaUniversità di CataniaCataniaItaly
  2. 2.Kiepenheuer-Institut für SonnenphysikSchöneckstr (KIS). 6FreiburgGermany
  3. 3.Osservatorio Astrofisico di CataniaIstituto Nazionale di Astrofisica (INAF)CataniaItaly
  4. 4.National Solar Observatory (NSO)SunspotUSA
  5. 5.Osservatorio Astronomico di RomaIstituto Nazionale di Astrofisica (INAF)Monte Porzio CatoneItaly
  6. 6.Institute of Theoretical AstrophysicsUniversity of OsloOsloNorway

Personalised recommendations