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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 two days with the Tenrife Infrared…

Solar and Stellar Astrophysics · Physics 2017-08-23 Jayant Joshi , Andreas Lagg , Johann Hirzberger , Sami K. Solanki

Recent observations have shown that the photometric and dynamic properties of granulation and of small-scale magnetic features depend on the amount of magnetic flux of the region they are embedded in. We analyze results from numerical Hydro…

Solar and Stellar Astrophysics · Physics 2015-06-17 Serena Criscuoli

Over the past five years, 2010-2015, we have observed, in the near infrared (IR), the maximum magnetic field strengths for 4145 sunspot umbrae. Herein we distinguish field strengths from field flux. (Most solar magnetographs measure flux).…

Solar and Stellar Astrophysics · Physics 2016-04-12 William Livingston , Fraser Watson

Aims. Convective collapse, a theoretically predicted process that intensifies existing weak magnetic fields in the solar atmosphere, was first directly observed in a single event by Nagata et al. (2008) using the high resolution Solar…

Solar and Stellar Astrophysics · Physics 2015-05-13 C. E. Fischer , A. G. de Wijn , R. Centeno , B. W. Lites , C. U. Keller

We investigate the vertical gradient of the magnetic field of sunspots in the photospheric layer. Independent observations were obtained with the SOT/SP onboard the Hinode spacecraft and with the TIP-2 mounted at the VTT. We apply…

Solar and Stellar Astrophysics · Physics 2017-03-01 Jayant Joshi , Andreas Lagg , Johann Hirzberger , Sami K. Solanki , Sanjiv K. Tiwari

We use joint observations obtained with the Hinode space observatory and the Interferometric Bidimensional Spectrometer (IBIS) installed at the DST of the NSO/SP to investigate the morphology and dynamics of (a) non-magnetic and (b)…

Solar and Stellar Astrophysics · Physics 2009-12-18 F. Wöger , S. Wedemeyer-Böhm , T. Rimmele

In this work, we study and quantify properties of strong-field small-scale convection and compare observed properties with those predicted by numerical simulations. We analyze spectropolarimetric 630.25 nm data from a unipolar ephemeral…

Solar and Stellar Astrophysics · Physics 2015-05-19 G. Narayan , G. B. Scharmer

We describe the characteristics and evolution of the magnetic field and chromospheric emission in an active region core observed by the Solar Optical Telescope on Hinode. Consistent with previous studies, we find that the moss is unipolar,…

Solar and Stellar Astrophysics · Physics 2015-05-19 David H. Brooks , Harry P. Warren , Amy R. Winebarger

Properties of transient horizontal magnetic fields (THMFs) in both plage and quiet Sun regions are obtained and compared. Spectro-polarimetric observations with the Solar Optical Telescope (SOT) on the Hinode satellite were carried out with…

Astrophysics · Physics 2009-11-13 Ryohko Ishikawa , Saku Tsuneta

The motions of small-scale magnetic flux elements in the solar photosphere can provide some measure of the Lagrangian properties of the convective flow. Measurements of these motions have been critical in estimating the turbulent diffusion…

Solar and Stellar Astrophysics · Physics 2018-02-27 Piyush Agrawal , Mark P. Rast , Milan Gosic , Luis R. Bellot Rubio , Matthias Rempel

Context: The determination of the magnetic field vector in quiescent solar prominences is possible by interpreting the Hanle and Zeeman effects in spectral lines. However, observational measurements are scarce and lack high spatial…

Solar and Stellar Astrophysics · Physics 2014-07-02 David Orozco Suárez , Andrés Asensio Ramos , Javier Trujillo Bueno

We present properties of intensity oscillations of a sunspot in the photosphere and chromosphere using G~band and CaIIH filtergrams from Hinode. Intensity power maps as function of magnetic field strength and frequency reveal reduction of…

Solar and Stellar Astrophysics · Physics 2015-02-17 Ankala Raja Bayanna , Shibu K Mathew , Brajesh Kumar , Rohan E Louis , Parameswaran Venkatakrishnan

The aim of this work is to identify the physical processes that occur in the network and contribute to its dynamics and heating. We model the network as consisting of individual flux tubes with a non-potential field structure that are…

Astrophysics · Physics 2009-11-10 S. S. Hasan , A. A. van Ballegoiijen , W. Kalkofen , O. Steiner

Small-scale, newly emerging internetwork (IN) magnetic fields are considered a viable source of energy and mass for the solar chromosphere and possibly the corona. Multiple studies show that single events of flux emergence can indeed…

Solar and Stellar Astrophysics · Physics 2025-08-28 Milan Gošić , Bart De Pontieu , Alberto Sainz Dalda

We analyze a time series of high angular resolution magnetograms of quiet Sun Inter-Network (IN) magnetic fields. These magnetograms have a spatial resolution better than 0.5 arcsec, a noise of some 20 G, and they have been obtained at the…

Astrophysics · Physics 2009-11-10 J. Sanchez Almeida

The existence of a turbulent small-scale solar surface dynamo is likely, considering existing numerical and laboratory experiments, as well as comparisons of a small-scale dynamo in MURaM simulations with Hinode observations. We find the…

Solar and Stellar Astrophysics · Physics 2010-03-19 Jonathan Pietarila Graham , Sanja Danilovic , Manfred Schuessler

We consider the possibility that cosmic magnetic field, instead of being uniformly distributed, is strongly correlated with the large scale structure of the universe. Then, the observed rotational measure of extra-galactic radio sources…

Astrophysics · Physics 2011-07-19 Dongsu Ryu , Hyesung Kang , Peter L. Biermann

A small decaying sunspot was observed with the Vacuum Tower Telescope (VTT) on Tenerife and the Japanese Hinode satellite. We obtained full Stokes scans in several wavelengths covering different heights in the solar atmosphere. Imaging time…

Solar and Stellar Astrophysics · Physics 2013-01-09 H. Balthasar , C. Beck , P. Gömöry , K. Muglach , K. G. Puschmann , T. Shimizu , M. Verma

Magnetic field emerges at the surface of the Sun as sunspots and active regions. This process generates a poloidal magnetic field from a rising toroidal flux tube, it is a crucial but poorly understood aspect of the solar dynamo. The…

Solar and Stellar Astrophysics · Physics 2016-07-19 Aaron C. Birch , Hannah Schunker , Douglas C. Braun , Robert Cameron , Laurent Gizon , Björn Löptien , Matthias Rempel

It is well known that the dominant frequency of oscillations in the solar photosphere is $\approx$3 mHz, which is the result of global resonant modes pertaining to the whole stellar structure. However, analyses of the horizontal motions of…

Solar and Stellar Astrophysics · Physics 2024-07-08 M. Berretti , M. Stangalini , G. Verth , S. Jafarzadeh , D. B. Jess , F. Berrilli , S. D. T. Grant , T. Duckenfield , V. Fedun