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Related papers: On the variation of solar coronal rotation using S…

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Srivastava et al. (2010) have observed a highly twisted coronal loop, which was anchored in AR10960 during the period 04:43 UT-04:52 UT on 4 June 2007. The loop length and radius are approximately 80 Mm and 4 Mm, with a twist of 11.5 $\pi$.…

Solar and Stellar Astrophysics · Physics 2015-06-12 A. K. Srivastava , G. J. J. Botha , T. D. Arber , P. Kayshap

Events in the solar corona are often widely separated in their timescales, which can allow them to be identified when they would otherwise be confused with emission from other sources in the corona. Methods for cleanly separating such…

Solar and Stellar Astrophysics · Physics 2016-02-01 Joseph Plowman

Understanding how the solar corona is structured is of fundamental importance to determining how the Sun's upper atmosphere is heated to high temperatures. Recent spectroscopic studies have suggested that an instrument with a spatial…

Solar and Stellar Astrophysics · Physics 2013-07-18 David H. Brooks , Harry P. Warren , Ignacio Ugarte-Urra , Amy R. Winebarger

(abridged) We investigate the long-term evolution of X-ray coronae of solar analogs based on high-resolution X-ray spectroscopy and photometry with XMM-Newton. Six nearby main-sequence G stars with ages between ~0.1 Gyr and \~1.6 Gyr and…

Astrophysics · Physics 2009-11-10 A. Telleschi , M. Guedel , K. Briggs , M. Audard , J. -U. Ness , S. L. Skinner

Following previous investigations by Giordano and Mancuso [1] and Mancuso and Giordano [2, 3] on the differential rotation of the solar corona as obtained through the analysis of the intensity time series of the O VI 1032 Ang. spectral line…

Solar and Stellar Astrophysics · Physics 2012-11-16 Salvatore Mancuso , Silvio Giordano

It is typically assumed that emission in the passbands of the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) is dominated by single or several strong lines from ions that under equilibrium conditions are…

Solar and Stellar Astrophysics · Physics 2017-10-23 Juan Martinez-Sykora , Bart De Pontieu , Paola Testa , Viggo Hansteen

We have analyzed 44.3M single muons collected by MACRO from 1991 through 2000 in 2,145 live days of operation. We have searched for the solar diurnal, apparent sidereal, and pseudo-sidereal modulation of the underground muon rate by…

Astrophysics · Physics 2008-11-26 The MACRO Collaboration , M. Ambrosio

Helioseismology has revealed that the angular velocity of the Sun increases with depth in the outermost 35 Mm of the Sun. Recently, we have shown that the logarithmic radial gradient ($\rm d\ln\Omega/\rm d\ln r $) in the upper 10~Mm is…

Solar and Stellar Astrophysics · Physics 2016-11-02 Atefeh Barekat , Jesper Schou , Laurent Gizon

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

We examined the structure near the solar limb in TRACE images of the continuum and in the 1600 and 171 A bands as well as in SDO images in the continuum (from HMI) and all AIA bands. The images in different wavelength bands were carefully…

Solar and Stellar Astrophysics · Physics 2019-07-31 C. E. Alissandrakis , A. Valentino

Three-minute oscillations over sunspot's umbra in AR 11131 were observed simultaneously in UV/EUV emission by SDO/AIA and in radio emission by Nobeyama Radioheliograph (NoRH). We use 24-hours series of SDO and 8-hours series of NoRH…

Solar and Stellar Astrophysics · Physics 2015-05-30 V. E. Reznikova , K. Shibasaki , R. A. Sych , V. M. Nakariakov

The relationships among coronal loop structures at different temperatures is not settled. Previous studies have suggested that coronal loops in the core of an active region are not seen cooling through lower temperatures and therefore are…

Solar and Stellar Astrophysics · Physics 2011-02-11 Ignacio Ugarte-Urra , Harry P. Warren , David H. Brooks

Coronal loops serve as the fundamental building blocks of the solar corona. Therefore, comprehending their properties is essential in unraveling the dynamics of the Sun's upper atmosphere. In this study, we conduct a comparative analysis of…

We present a new method for performing differential emission measure (DEM) inversions on narrow-band EUV images from the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO). The method yields positive definite…

Solar and Stellar Astrophysics · Physics 2015-07-15 Mark C. M. Cheung , P. Boerner , C. J. Schrijver , P. Testa , F. Chen , H. Peter , A. Malanushenko

Helioseismic signatures of dynamo waves have recently been discovered in variations of the solar differential rotation, offering valuable insights into the type of dynamo mechanism operating in the solar convection zone. To characterize…

Solar and Stellar Astrophysics · Physics 2025-05-19 Krishnendu Mandal , Alexander G. Kosovichev , Valery V. Pipin , Sylvain G. Korzennik

We use high-resolution images of the sun obtained by the SDO/AIA instrument to study the evolution of the coronal loops in a flaring solar active region. During 15 February 2011 a X-2.2 class flare occurred in NOAA 11158, a…

Solar and Stellar Astrophysics · Physics 2015-06-04 S. Gosain

The average Doppler shift shown by spectral lines formed from the chromosphere to the corona reveals important information on the mass and energy balance of the solar atmosphere, providing an important observational constraint to any models…

Solar and Stellar Astrophysics · Physics 2011-09-22 Neda Dadashi , Luca Teriaca , Sami K. Solanki

Active regions often show S-shaped structures in the corona called sigmoids. These are highly sheared and twisted loops formed along the polarity inversion line. They are considered to be one of the best pre-eruption signatures for CMEs.…

Solar and Stellar Astrophysics · Physics 2021-03-31 Sargam M. Mulay , Durgesh Tripathi , Helen Mason

Coronal waves, significant solar phenomena, act as diagnostic tools for scientists studying solar atmosphere properties. Here, we present a novel observation detailing how a coronal wave event, associated with an X5.0 class flare,…

We consider the problem of automatically (and robustly) isolating and extracting information about waves and oscillations observed in EUV image sequences of the solar corona with a view to near real-time application to data from the…

Astrophysics · Physics 2009-11-13 Scott W. McIntosh , Bart De Pontieu , Steven Tomczyk