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Related papers: Analysis of spatially deconvolved polar faculae

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Observations of cool stars reveal dark spot-like features on their surfaces. Compared to sunspots, starspots can be bigger or cover a larger fraction of the stellar surface. While sunspots appear only at low latitudes, starspots are also…

Solar and Stellar Astrophysics · Physics 2014-12-24 Rakesh K. Yadav , Thomas Gastine , Ulrich R. Christensen , Ansgar Reiners

The degree of linear polarization has recently been found to show wide random variations over the solar disk. These variations are presumably at least partly due to fluctuations in the flux density of turbulent photospheric magnetic fields…

Astrophysics · Physics 2007-05-23 K. Petrovay

We present spectropolarimetric measurements of dark-cored penumbral filaments taken with Hinode at a resolution of 0.3". Our observations demonstrate that dark-cored filaments are more prominent in polarized light than in continuum…

We employ the magnetic and velocity fields from turbulent dynamo simulations to synthesize the polarization of a typical photospheric line. The synthetic Stokes profiles have properties in common with those observed in the quiet Sun. The…

Astrophysics · Physics 2009-11-07 J. Sánchez Almeida , T. Emonet , F. Cattaneo

Solar flares - which are the most prominent manifestation of the solar activity - typically manifest themselves as a single or a set of luminous arcs (magnetic flux tubes) rooted in regions of opposite polarity in the photosphere. However,…

Solar and Stellar Astrophysics · Physics 2023-10-25 Yurii V. Dumin , Boris V. Somov

The detailed investigation of the polar magnetic field and its time evolution is one of the major achievements of Hinode. Precise measurements of the polar magnetic field are essential for understanding the solar cycle, as they provide…

The structure of the photospheric vector magnetic field below a dark filament on the Sun is studied using the observations of the Spectro-Polarimeter attached to the Solar Optical Telescope onboard Hinode. Special attention is paid to…

Solar and Stellar Astrophysics · Physics 2019-03-20 Takaaki Yokoyama , Yukio Katsukawa , Masumi Shimojo

We have obtained the first time-resolved, disc-integrated observations of Earth's poles with the Deep Impact spacecraft as part of the EPOXI Mission of Opportunity. These data mimic what we will see when we point next-generation space…

We interpret penumbral filaments as due to convection in field-free, radially aligned gaps just below the visible surface of the penumbra, intruding into a nearly potential field above. This solves the classical discrepancy between the…

Astrophysics · Physics 2016-08-30 H. C. Spruit , G. B. Scharmer

Magnetic-field reconnection is believed to play a fundamental role in magnetized plasma systems throughout the Universe1, including planetary magnetospheres, magnetars and accretion disks around black holes. This letter present extreme…

Solar and Stellar Astrophysics · Physics 2015-02-06 Yang Su , Astrid M. Veronig , Gordon D. Holman , Brian R. Dennis , Tongjiang Wang , Manuela Temmer , Weiqun Gan

This work focus on the first results on the identification and characterization of periodic plasma density fluctuations in the outer corona, observed in STEREO-A COR1 white-light image time series. A 2D reconstruction of the spatial…

Solar and Stellar Astrophysics · Physics 2015-06-15 D. Telloni , R. Ventura , P. Romano , D. Spadaro , E. Antonucci

The formation and the temporal evolution of a bipolar moving magnetic feature (MMF) was studied with high spatial and temporal resolution. The photometric properties were observed with the New Solar Telescope at Big Bear Solar Observatory…

Solar and Stellar Astrophysics · Physics 2015-06-05 Eun-Kyung Lim , Vasyl Yurchyshyn , Philip Goode

We investigate the orientation of the photospheric magnetic fields in the solar polar region using observations from the Helioseismic and Magnetic Imager (HMI). Inside small patches of significant polarization, the inferred magnetic field…

Solar and Stellar Astrophysics · Physics 2021-06-04 Xudong Sun , Yang Liu , Ivan Milić , Ana Belén Griñón Marín

The magnetic fields and dynamical processes in the solar polar regions play a crucial role in the solar magnetic cycle and in supplying mass and energy to the fast solar wind, ultimately being vital in controlling solar activities and…

Stellar activity is the major roadblock on the path to finding true Earth-analogue planets with the Doppler technique. Thus, identifying new indicators that better trace magnetic activity (i.e. faculae and spots) is crucial to aid in…

Polar coronal plumes seen during solar eclipses can now be studied with space-borne telescopes and spectrometers. We briefly discuss such observations from space with a view to understanding their plasma characteristics. Using these…

Solar and Stellar Astrophysics · Physics 2015-05-13 K. Wilhelm , B. N. Dwivedi , W. Curdt

The Sun provides an excellent natural laboratory for nonlinear phenomena. We use motions of magnetic bright points on the solar surface, at the smallest scales yet observed, to study the small scale dynamics of the photospheric plasma. The…

Astrophysics · Physics 2009-11-06 J. K. Lawrence , A. C. Cadavid , A. Ruzmaikin , T. E. Berger

The expansion with height of the solar photospheric magnetic field and the plasma flows is investigated for three isolated bright points (BPs). The BPs were observed simultaneously with 3 instruments at the GREGOR telescope: (1) filtergrams…

Solar and Stellar Astrophysics · Physics 2019-10-09 Christoph Kuckein

We gave an extensive study for the quasi-periodic perturbations on the time profiles of the line of sight (LOS) magnetic field in 10x10 sub-areas in a solar plage region (corresponds to a facula on the photosphere). The perturbations are…

Solar and Stellar Astrophysics · Physics 2022-04-20 Haisheng Ji , Parida Hashim , Zhenxiang Hong , Zhe Xu , Jinhua Shen , Kaifan Ji , Wenda Cao

Solar variability investigations that include magnetic energy coupling are paramount to solving many key solar/stellar physics problems, particularly for understanding the temporal variability of magnetic energy redistribution and heating…

Solar and Stellar Astrophysics · Physics 2016-12-28 N. Brice Orange , David L. Chesny , Bruce Gendre , David C. Morris , Hakeem M. Oluseyi