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Related papers: Downflows in sunspot umbral dots

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Umbral dots (UDs) are small-scale convective intrusions in the umbral core of sunspots and pores. Different methods have been used in the past to determine the physical properties of UDs. One of the methods typically used is multi-level…

Solar and Stellar Astrophysics · Physics 2026-05-27 Rohan Eugene Louis , Amit Chaturvedi

Context. Observations of many active regions show a slow systematic outflow/upflow from their edges lasting from hours to days. At present no physical explanation has been proven, while several suggestions have been put forward. Aims. This…

Solar and Stellar Astrophysics · Physics 2021-08-25 K. Galsgaard , M. S. Madjarska , K. Vanninathan , Z. Huang , M. Presmann

We investigated the role of photospheric plasma motions in the formation and evolution of polar magnetic patches using time-sequence observations with high spatial resolution. The observations were obtained with the spectropolarimeter on…

Solar and Stellar Astrophysics · Physics 2015-06-23 Anjali John Kaithakkal , Y. Suematsu , M. Kubo , Y. Iida , D. Shiota , S. Tsuneta

Context. Bright points (BPs) are small-scale, magnetic features ubiquitous across the solar surface. Previously, we have observed and noted their properties for quiet Sun regions. Here, we determine the dynamic properties of BPs using…

Solar and Stellar Astrophysics · Physics 2014-07-02 Peter H. Keys , Mihalis Mathioudakis , David B. Jess , Duncan H. Mackay , Francis P. Keenan

Convective flows are known as the prime means of transporting magnetic fields on the solar surface. Thus, small magnetic structures are good tracers of the turbulent flows. We study the migration and dispersal of magnetic bright features…

We determined the direction and strength of the photospheric and lower chromospheric magnetic field in the umbra and penumbra of a sunspot from inversions of spectropolarimetric observations of photospheric lines at 617\,nm and 1565\,nm,…

Solar and Stellar Astrophysics · Physics 2019-03-20 C. Beck , D. P. Choudhary

Sunspots harboring umbrae of both magnetic polarities within a common penumbra (delta-spots) are often but not always related to flares. We present first near-infrared (NIR) observations (Fe I 1078.3 nm and Si I 1078.6 nm spectra) obtained…

Solar and Stellar Astrophysics · Physics 2015-06-18 H. Balthasar , C. Beck , R. E. Louis , M. Verma , C. Denker

The generation of magnetic flux in the solar interior and its transport to the outer solar atmosphere will be in the focus of solar physics research for the next decades. One key-ingredient is the process of magnetic flux emergence into the…

Solar and Stellar Astrophysics · Physics 2015-05-20 Rolf Schlichenmaier , Nazaret Bello González , Reza Rezaei

Magnetic fields emerging from the Sun's interior carry information about physical processes of magnetic field generation and transport in the convection zone. Soon after appearance on the solar surface the magnetic flux gets concentrated in…

Solar and Stellar Astrophysics · Physics 2009-11-13 A. G. Kosovichev

Context. Fully fledged penumbrae have been widely studied both observationally and theoretically. Yet the relatively fast process of penumbra formation has not been studied closely with high spatial resolution. Aims. We investigate the…

Solar and Stellar Astrophysics · Physics 2024-06-05 M. García-Rivas , J. Jurčák , N. Bello González , J. M. Borrero , R. Schlichenmaier , P. Lindner

Solar granules are bright patterns surrounded by dark channels called intergranular lanes in the solar photosphere and are a manifestation of overshooting convection. Observational studies generally find stronger upflows in granules and…

Solar and Stellar Astrophysics · Physics 2017-11-01 T. Oba , T. L. Riethmüller , S. K. Solanki , Y. Iida , C. Quintero Noda , T. Shimizu

Spectropolarimetric observations from Sunrise II/IMaX obtained in June 2013 are used for a statistical analysis to determine the physical properties of moving magnetic features (MMFs) observed near a pore. MMFs of the same and opposite…

In this contribution we describe some recent observations of high-speed magnetized flows in the quiet Sun granulation. These observations were carried out with the Imaging Magnetograph eXperiment (IMaX) onboard the stratospheric balloon…

The chromosphere above active regions (ARs) on the Sun hosts magnetized supersonic downflows. Studies of these supersonic downflows help to decipher the magnetic fine structure and dynamics of the chromosphere. We perform a statistical…

Solar and Stellar Astrophysics · Physics 2022-07-26 K. Sowmya , A. Lagg , S. K. Solanki , J. S. Castellanos Durán

Downflows at supersonic speeds have been observed in the transition region (TR) above sunspots for more than three decades. These downflows are often seen in different TR spectral lines above sunspots. We have performed a statistical…

Solar and Stellar Astrophysics · Physics 2018-06-27 Tanmoy Samanta , Hui Tian , Debi Prasad Choudhary

We present a subset of multi-wavelengths observations obtained with the Japanese Hinode mission, the Solar Dynamics Observatory (SDO), and the Vacuum Tower Telescope (VTT) at Observatorio del Teide, Tenerife, Spain during the time period…

Solar and Stellar Astrophysics · Physics 2015-06-03 M. Verma , H. Balthasar , N. Deng , C. Liu , T. Shimizu , H. Wang , C. Denker

High-resolution spectropolarimetric observations of active region NOAA 11271 were obtained with the spectro-polarimeter on board Hinode to analyze the properties of an anomalous flow in the photosphere in a sunspot penumbra. We detect a…

Solar and Stellar Astrophysics · Physics 2014-10-29 Rohan E. Louis , Christian Beck , Shibu K. Mathew , P. Venkatakrishnan

The analysis of the meridional displacement velocity of individual solar pores and sunspots has been performed. In the period May 2010\,-\,March 2025 of observations in the continuum of the \textit{Solar Dynamics Observatory/Helioseismic…

Solar and Stellar Astrophysics · Physics 2025-07-01 Andrey Tlatov , Kseniya Tlatova

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

We analyzed the full Stokes spectra using simultaneous measurements of the photospheric (FeI 630.15 and 630.25 nm) and chromospheric (MgI b2 517.27 nm) lines. The data were obtained with the HAO/NSO Advanced Stokes Polarimeter, about a near…

Solar and Stellar Astrophysics · Physics 2015-05-19 Na Deng , Debi Prasad Choudhary , K. S. Balasubramaniam