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Related papers: Steps toward a high precision solar rotation profi…

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Using the Solar Optical Observing Network (SOON) sunspot-group data for the period 1985-2010, the variations in the annual mean equatorial-rotation rates of the sunspot groups are determined and compared with the known variations in the…

Solar and Stellar Astrophysics · Physics 2013-07-29 J. Javaraiah

Differential rotation is a key driver of magnetic activity and dynamo processes in the Sun and other stars, especially as the rate differs across the solar layers, but also in active regions. We aim to accurately quantify the velocity at…

Context. Magnetic Bright Points (MBPs) are small-scale magnetic features in the solar photosphere. They may be a possible source of coronal heating by rapid footpoint motions that cause magnetohydrodynamical waves. The number and size…

Solar and Stellar Astrophysics · Physics 2014-11-20 D. Utz , A. Hanslmeier , C. Möstl , R. Muller , A. Veronig , H. Muthsam

Many competing models for the coronal heating and acceleration mechanisms of the high-speed solar wind depend on the solar magnetic field and plasma structure in the corona within heliocentric distances of $5R_\odot$. We report on sensitive…

Solar and Stellar Astrophysics · Physics 2015-06-16 Jason E. Kooi , Patrick D. Fischer , Jacob J. Buffo , Steven R. Spangler

The present work is an effort to investigate possible radial variations in the solar coronal rotation by analyzing the solar radio emission data at 15 different frequencies (275-1755 MHz) for the period starting from July 1994 to May 1999.…

Solar and Stellar Astrophysics · Physics 2021-05-28 Vivek Kumar Singh , Satish Chandra , Sanish Thomas , Som Kumar Sharma , Hari Om Vats

Determining the relative brightness of the solar corona is one of the most critical stages in solar eclipse studies. For this purpose, images taken with different exposures and polarization angles in white-light observations are used. The…

Solar and Stellar Astrophysics · Physics 2017-12-01 Hikmet Çakmak

Current coronal holes segmentation methods typically rely on image thresholding and require non-trivial image pre- and post-processing. We have trained a neural network that accurately isolates CHs from SDO/AIA 193 Angstrom solar disk…

Solar and Stellar Astrophysics · Physics 2018-10-17 E. Illarionov , A. Tlatov

The {\it Wide-field Imager for Solar Probe} (WISPR) on {\it Parker Solar Probe} (PSP), observing in white light, has a fixed angular field of view, extending from 13.5$^{\circ}$ to 108$^{\circ}$ from the Sun and approximately 50$^{\circ}$…

Solar and Stellar Astrophysics · Physics 2020-11-04 P. C. Liewer , J. Qiu , P. Penteado , J. R. Hall , A. Vourlidas , R. A. Howard

We describe a new algorithm for reconstruction of Differential Emission Measures (DEMs) in the solar corona. Although a number of such algorithms currently exist, they can have difficulty converging for some cases, and can be complex, slow,…

Solar and Stellar Astrophysics · Physics 2020-12-11 Joseph Plowman , Amir Caspi

Context. The Sun's complex corona is the source of the solar wind and interplanetary magnetic field. While the large scale morphology is well understood, the impact of variations in coronal properties on the scale of a few degrees on…

Chromospheric differential rotation is a key component in comprehending the atmospheric coupling between the chromosphere and the photosphere at different phases of the solar cycle. In this study, we therefore utilize the newly calibrated…

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

The characterization of solar surface differential rotation (SDR) from disk-integrated chromospheric measurements has important implications for the study of differential rotation and dynamo processes in other stars. Some chromospheric…

Solar and Stellar Astrophysics · Physics 2015-06-11 Luca Bertello , Alexei A. Pevtsov , A. Pietarila

We present a comprehensive characterization of 26 CME-driven compressive waves known as Coronal Bright Fronts (CBFs) observed in the low solar corona between 2010 and 2017. These CBFs have been found to be associated with SEP events near…

Solar and Stellar Astrophysics · Physics 2024-04-05 Mohamed Nedal , Kamen Kozarev , Rositsa Miteva , Oleg Stepanyuk , Momchil Dechev

We present the construction of a new white-light coronal brightness index (CBI) from the entire archive of observations recorded by the Large Angle Spectrometric Coronagraph (LASCO) C2 camera between 1996 and 2017, comprising two full solar…

Solar and Stellar Astrophysics · Physics 2020-03-11 Karl Battams , Russell A. Howard , Hillary A. Dennison , Robert S. Weigel , Judith L. Lean

Coronal loops are building blocks of solar active regions. However, their formation mechanism is still not well understood. Here we present direct observational evidence for the formation of coronal loops through magnetic reconnection as…

Solar and Stellar Astrophysics · Physics 2021-07-14 Zhenyong Hou , Hui Tian , Hechao Chen , Xiaoshuai Zhu , Zhenghua Huang , Xianyong Bai , Jiansen He , Yongliang Song , Lidong Xia

Magnetic Bright Points (MBPs) in the internetwork are among the smallest objects in the solar photosphere and appear bright against the ambient environment. An algorithm is presented that can be used for the automated detection of the MBPs…

Solar and Stellar Astrophysics · Physics 2015-05-13 P. J. Crockett , D. B. Jess , M. Mathioudakis , F. P. Keenan

Context. The Sun shows an activity cycle that is caused by its varying global magnetic field. During a solar cycle, sunspots, i.e. extended regions of strong magnetic fields, occur in activity belts that are slowly migrating from middle to…

Solar and Stellar Astrophysics · Physics 2015-11-25 D. Utz , R. Muller , S. Thonhofer , A. Veronig , A. Hanslmeier , M. Bodnárová , M. Bárta , J. C. del Toro Iniesta

Our aim is to determine the plasma properties of a coronal bright point and compare its magnetic topology extrapolated from magnetogram data with its appearance in X-ray images. We analyse spectroscopic data obtained with EIS/Hinode, Ca II…

Astrophysics · Physics 2008-10-07 D. Pérez-Suárez , R. C. Maclean , J. G. Doyle , M. S. Madjarska

The Solar Orbiter mission, with an orbit outside the Sun Earth line and leaving the ecliptic plane, opens up opportunities for the combined analysis of measurements obtained by solar imagers and spectrometers. For the first time, different…

Solar and Stellar Astrophysics · Physics 2021-11-24 O. Podladchikova , L. Harra , K. Barczynski , C. H. Mandrini , F. Auchere , D. Berghmans , E. Buchlin , L. Dolla , M. Mierla , S. Parenti , L. Rodriguez
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