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We report the discovery of supersonic downflows in a sunspot light bridge using measurements taken with the spectropolarimeter on board the Hinode satellite. The downflows occur in small patches close to regions where the vector magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-14 Rohan Eugene Louis , Luis R. Bellot Rubio , Shibu K. Mathew , P. Venkatakrishnan

A light bridge is a prominent structure commonly observed within a sunspot. Its presence usually triggers a wealth of dynamics in a sunspot, and has a lasting impact on sunspot evolution. However, the fundamental structure of light bridges…

Solar and Stellar Astrophysics · Physics 2020-04-15 Song Feng , Yuhu Miao , Ding Yuan , Zhongquan Qu , Valery M. Nakariakov

We present the results obtained by analyzing 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, relevant to a large sunspot…

A sunspot acts as a waveguide in response to the dynamics of the solar interior; the trapped waves and oscillations could reveal its thermal and magnetic structures. We study the oscillations in a sunspot intruded by a light bridge, the…

Solar and Stellar Astrophysics · Physics 2016-10-19 Ding Yuan , Robert W. Walsh

We present spectropolarimetric analysis of umbral dots and a light bridge fragment that show dark lanes in G-band images. Umbral dots show upflow as well as associated positive Stokes V area asymmetry in their central parts. Larger umbral…

Astrophysics · Physics 2009-11-13 Lokesh Bharti , Chandan Joshi , S. N. A. Jaaffrey , Rajmal Jain

Aims: We search for penumbral magnetic fields of opposite polarity and for their correspondence with downflows. Methods: We used spectropolarimetric HINODE data of a spot very close to disk center to suppress the horizontal velocity…

Solar and Stellar Astrophysics · Physics 2015-06-12 Morten Franz , Rolf Schlichenmaier

High-resolution broadband filtergrams of active region NOAA 11271 in Ca ii H and G band were obtained with the Solar Optical Telescope on board Hinode to identify the physical driver responsible for the dynamic and small-scale chromospheric…

Solar and Stellar Astrophysics · Physics 2015-06-19 Rohan E. Louis , Christian Beck , Kiyoshi Ichimoto

Recent high resolution spectropolarimetric observations from Hinode detected the presence of supersonic downflows in a sunspot light bridge (Louis et al. 2009). These downflows occurred in localized patches, close to regions where the field…

Solar and Stellar Astrophysics · Physics 2012-06-21 Rohan E. Louis , Luis R. Bellot Rubio , Shibu K. Mathew , P. Venkatakrishnan

We analyze a set of full Stokes profile observations of the flaring active region NOAA 10808 recorded with the Vector-Spectromagnetograph (VSM) of the SOLIS facility. We aim to quantify transient and permanent changes in the magnetic field…

Solar and Stellar Astrophysics · Physics 2015-06-11 C. E. Fischer , C. U. Keller , F. Snik , L. Fletcher , H. Socas-Navarro

A precise knowledge of the surface structure of sunspots is essential to construct adequate input models for helioseismic inversion tools. We summarize our recent findings about the velocity and magnetic field in and around sunspots using…

Solar and Stellar Astrophysics · Physics 2015-03-13 Morten Franz

Solar Optical Telescope onboard Hinode observed a sunspot (AR 11836) with two light bridges (LBs) on 31 Aug 2013. We analysed a 2-hour \ion{Ca}{2} H emission intensity data set and detected strong 5-min oscillation power on both LBs and in…

Solar and Stellar Astrophysics · Physics 2015-06-22 Ding Yuan , Valery M. Nakariakov , Zhenghua Huang , Bo Li , Jiangtao Su , Yihua Yan , Baolin Tan

The penumbra is ideally suited to challenge our understanding of magnetohydrodynamics. The energy transport takes place as magnetoconvection in inclined magnetic fields under the effect of strong radiative cooling at the surface. The…

Astrophysics · Physics 2007-05-23 R. Schlichenmaier , D. A. N. Mueller , C. Beck

A sunspot penumbra is observationally examined to reveal properties of small-scale flow structures and how they are related to the filamentary magnetic structures and the Evershed flow. We also study how the photospheric dynamics is related…

Solar and Stellar Astrophysics · Physics 2015-05-19 Y. Katsukawa , J. Jurcak

We investigate the spatial distribution of magnetic polarities in the penumbra of a spot observed very close to disk center. High-spatial resolution, high-cadence magnetograms taken with the Narrowband Filter Imager aboard Hinode are used…

Astrophysics · Physics 2009-11-13 A. Sainz Dalda , L. R. Bellot Rubio

Light bridge (LB) is bright structure crossing the umbra of sunspots and associated to the breakup or assembly of sunspots. In this paper, a LB is presented and studied using the observatory data obtained by {\it Hinode} satellites.…

Solar and Stellar Astrophysics · Physics 2019-05-07 S. Liu , D. Liu

The various mechanisms of magneto-convective energy transport determines the structure of sunspots and active regions. We characterise the appearance of light bridges and other fine-structure details and elaborate on their…

The satellite Hinode has recently revealed penumbral structures with a magnetic polarity opposite to the main sunspot polarity. They may be a direct confirmation of magnetic field lines and mass flows returning to the solar interior…

Solar and Stellar Astrophysics · Physics 2015-05-14 J. Sanchez Almeida , K. Ichimoto

Light bridges (LBs) are relatively bright structures that divide sunspot umbrae into two or more parts. Chromospheric LBs are known to be associated with various activities including fan-shaped jet-like ejections and brightenings. Although…

Solar and Stellar Astrophysics · Physics 2020-12-02 Eun-Kyung Lim , Heesu Yang , Vasyl Yurchyshyn , Jongchul Chae , Donguk Song , Maria S. Madjarska

Dynamical jets are generally found on Light bridges (LBs), which are key to studying sunspots decays. So far, their formation mechanism is not fully understood. In this paper, we used state-of-the-art observations from the Goode Solar…

Solar and Stellar Astrophysics · Physics 2019-01-16 Xianyong Bai , Hector Socas-Navarro , Daniel Nóbrega-Siverio , Jiangtao Su , Yuanyong Deng , Dong Li , Wenda Cao , Kaifan Ji

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 its evolution in the photosphere and…

Solar and Stellar Astrophysics · Physics 2015-10-21 Rohan E. Louis , Luis R. Bellot Rubio , Jaime de la Cruz Rodriguez , Hector Socas-Navarro , Ada Ortiz
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