Three-dimensional structure of a sunspot light bridge

  title={Three-dimensional structure of a sunspot light bridge},
  author={Tobias Felipe and Manel Collados and Elena Khomenko and Christoph Kuckein and Andr{\'e}s Asensio Ramos and Horst Balthasar and Thomas Berkefeld and Carsten Denker and Alex J. Feller and Morten Franz and Albrecht W. Hofmann and Christoph Kiess and A. Lagg and Harald E. Nicklas and David Orozco Su'arez and Adur Pastor Yabar and Reza Rezaei and Rolf Schlichenmaier and David Schmidt and Wolfgang Schmidt and Michael Sigwarth and Michal Sobotka and Sami K. Solanki and Dirk Soltau and Jurgen Staude and Klaus G. Strassmeier and R. Volkmer and Oskar von der Luhe and Torsten A. Waldmann},
  journal={Astronomy and Astrophysics},
Context. Active regions are the most prominent manifestations of solar magnetic fields; their generation and dissipation are fundamental problems in solar physics. Light bridges are commonly present during sunspot decay, but a comprehensive picture of their role in the removal of the photospheric magnetic field is still lacking. Aims. We study the three-dimensional configuration of a sunspot, and in particular, its light bridge, during one of the last stages of its decay. Methods. We present… 
Spiral-shaped wavefronts in a sunspot umbra
Context. Solar active regions show a wide variety of oscillatory phenomena. The presence of the magnetic field leads to the appearance of several wave modes whose behavior is determined by the
Three-dimensional magnetic structure of a sunspot: comparison of the photosphere and upper chromosphere
We investigate the magnetic field of a sunspot in the upper chromosphere and compare it to the field's photospheric properties. We observed the main leading sunspot of the active region NOAA 11124 on
Long-term evolution of three light bridges developed on the same sunspot
One important feature of sunspots is the presence of light bridges. These structures are elongated and bright (as compared to the umbra) features that seem to be related to the formation and
Observational Evidence of a Flux Rope within a Sunspot Umbra
We observed an elongated filamentary bright structure inside the umbra of the big sunspot in active region NOAA 12529, which differs from the light bridges usually observed in sunspots for its
Light bridges can suppress the formation of coronal loops
A light bridge is a magnetic intrusion into a sunspot, it interacts with the main magnetic field and excites a variety of dynamical processes. In the letter, we studied magnetic connectivity
Structure of sunspot light bridges in the chromosphere and transition region
Light bridges (LBs) are elongated structures with enhanced intensity embedded in sunspot umbra and pores. We studied the properties of a sample of 60 LBs observed with the Interface Region Imaging
Peculiarities of the Dynamics of Solar NOAA Active Region 12673
The dynamics of active region (AR) 12673 is qualitatively studied using observational data obtained with the Helioseismic and Magnetic Imager of the Solar Dynamics Observatory on August 31--September
Signatures of the impact of flare-ejected plasma on the photosphere of a sunspot light bridge
We investigate the properties of a sunspot light-bridge, focusing on the changes produced by the impact of a plasma blob ejected from a C-class flare. We observed a sunspot in active region NOAA
Height variation of magnetic field and plasma flows in isolated bright points
Aims. The expansion with height of the solar photospheric magnetic field and the plasma flows is investigated for three isolated bright points (BPs). Methods. The BPs were observed simultaneously
Spectropolarimetric analysis of an active region filament
Aims. The determination of the magnetic filed vector in solar filaments is made possible by interpreting the Hanle and Zeeman effects in suitable chromospheric spectral lines like those of the He I


The Observation of Sunspot Light-Bridge Structure and Dynamics
We present very high resolution multiwavelength images of a sunspot light bridge in NOAA Active Region 10132 taken at the Swedish 1 m Solar Telescope on La Palma on 2002 September 25. The adaptive
Three-Dimensional Structure of the Active Region Photosphere as Revealed by High Angular Resolution
Blue continuum images of active regions at ∼ 60° from the center of the solar disk obtained with the new Swedish 1-m Solar Telescope reveal heretofore unreported structure of the magnetized solar
Small-scale magnetic flux emergence in a sunspot light bridge
We analyse a sequence of high-resolution spectropolarimetric observations of a sunspot taken at the 1-m SST, to determine the nature of flux emergence in a light bridge and the processes related to
Vigorous convection in a sunspot granular light bridge
Context. Light bridges are the most prominent manifestation of convection in sunspots. The brightest representatives are granular light bridges composed of features that appear to be similar to
The Vector Magnetic Fields and Thermodynamics of Sunspot Light Bridges: The Case for Field-free Disruptions in Sunspots
We present observations with the Advanced Stokes Polarimeter of 11 light bridges in sunspots of various ages and sizes, all very close to disk center. Full vector spectropolarimetry and a nonlinear
The three-dimensional structure of sunspots : I. The height dependence of the magnetic field
Aims. We investigate the height dependence of the magnetic field of a sunspot, which has been until now a controversial issue. Methods. Full-Stokes profiles of a sunspot, derived from infrared
Active region fine structure observed at 0.08 arcsec resolution
Context. The various mechanisms of magneto-convective energy transport determine the structure of sunspots and active regions. Aims. We characterise the appearance of light bridges and other
The magnetic canopy above light bridges
An analysis of high-resolution Stokes observations of two light bridges in active region NOAA 8990 is presented. The observations were recorded with the La Palma Stokes Polarimeter attached to the
Light Bridge in a Developing Active Region. I. Observation of Light Bridge and its Dynamic Activity Phenomena
Light bridges, the bright structures that divide the umbra of sunspots and pores into smaller pieces, are known to produce a wide variety of activity events in solar active regions (ARs). It is also
Flow Field Evolution of a Decaying Sunspot
We study the evolution of the flows and horizontal proper motions in and around a decaying follower sunspot based on time sequences of two-dimensional spectroscopic observations in the visible and