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Related papers: On active region loops: Hinode/EIS observations

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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…

One proposed resolution to the long-standing problem of solar coronal heating involves the buildup of magnetic energy in the corona due to turbulent motions at the photosphere that braid the coronal field, and the subsequent release of this…

Solar and Stellar Astrophysics · Physics 2015-05-27 D. I. Pontin , G. Hornig

Variations in the propagation of globally-propagating disturbances (commonly called "EIT waves") through the low solar corona offer a unique opportunity to probe the plasma parameters of the solar atmosphere. Here, high-cadence observations…

Solar and Stellar Astrophysics · Physics 2015-06-16 David M. Long , David R. Williams , Stéphane Régnier , Louise K. Harra

We report on the detection (10 \sigma) of 917 events of long-period (3 to 16 hours) intensity pulsations in the 19.5 nm passband of the SOHO Extreme ultraviolet Imaging Telescope. The data set spans from January 1997 to July 2010, i.e the…

Solar and Stellar Astrophysics · Physics 2014-03-05 F. Auchère , K. Bocchialini , J. Solomon , E. Tison

It is recently noted that solar eruptions can be associated with the contraction of coronal loops that are not involved in magnetic reconnection processes. In this paper, we investigate five coronal eruptions originating from four sigmoidal…

Solar and Stellar Astrophysics · Physics 2015-06-11 Rui Liu , Chang Liu , Tibor Török , Yuming Wang , Haimin Wang

Magnetohydrodynamic (MHD) waves and/or the braiding of magnetic field lines are largely thought to be responsible for heating the solar corona, both being mechanisms which are driven by the Sun's photospheric magnetic field. Recent…

It remains unclear which physical processes are responsible for the dramatic increase with height of the temperature in stellar atmospheres, known as the chromospheric ($\sim$10,000 K) and coronal (several million K) heating problems.…

Solar and Stellar Astrophysics · Physics 2022-11-17 Souvik Bose , Bart De Pontieu , Viggo Hansteen , Alberto Sainz Dalda , Sabrina Savage , Amy Winebarger

A set of co-aligned high resolution images from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) is used to investigate propagating disturbances (PDs) in warm fan loops at the periphery of a non-flaring…

Solar and Stellar Astrophysics · Physics 2015-06-17 Vadim M. Uritsky , Joseph M. Davila , Nicholeen M. Viall , Leon Ofman

The term `solar tornadoes' has been used to describe apparently rotating magnetic structures above the solar limb, as seen in high resolution images and movies from the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics…

Solar and Stellar Astrophysics · Physics 2015-09-30 Peter Levens , Nicolas Labrosse , Lyndsay Fletcher , Brigitte Schmieder

In coronal loop modeling, it is commonly assumed that the loops are semi-circular with a uniform cross-sectional area. However, observed loops are rarely semi-circular, and extrapolations of the magnetic field show that the field strength…

Solar and Stellar Astrophysics · Physics 2022-07-20 Jeffrey W. Reep , Ignacio Ugarte-Urra , Harry P. Warren , Will T. Barnes

Coronal loops generally trace magnetic lines of force in the upper solar atmosphere. Understanding the loop morphology and its temporal evolution has implications for coronal heating models that rely on plasma heating due to reconnection at…

Solar and Stellar Astrophysics · Physics 2025-01-29 B. Ram , L. P. Chitta , S. Mandal , H. Peter , F. Plaschke

The study examines the heating profile of hot solar transition region loops, particularly focusing on transient brightenings observed in IRIS 1400{\AA} slit-jaw images. The findings challenge the adequacy of simplistic, singular heating…

Solar and Stellar Astrophysics · Physics 2024-05-15 Shah Mohammad Bahauddin , Stephen J Bradshaw

To simulate the energy balance of coronal plasmas on macroscopic scales, we often require the specification of the coronal heating mechanism in some functional form. To go beyond empirical formulations and to build a more physically…

Solar and Stellar Astrophysics · Physics 2016-12-14 Cooper Downs , Roberto Lionello , Zoran Mikić , Jon A. Linker , Marco Velli

A detailed analysis of a coronal loop oscillation event is presented, using data from the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) for the first time. The loop oscillation event occurred on 2010 Oct…

Solar and Stellar Astrophysics · Physics 2015-05-28 Markus J. Aschwanden , Carolus J. Schrijver

The excess temperature of the solar corona over the photosphere poses a challenge. Multiple energetic events contribute to maintaining the corona at such high temperatures. The energy released in different events can vary across several…

Solar and Stellar Astrophysics · Physics 2023-02-21 Abhishek Rajhans

The condensations composing coronal rain, falling down along loop-like structures observed in cool chromospheric lines such as H$\alpha$ and \ion{Ca}{2} H, have long been a spectacular phenomenon of the solar corona. However, considered a…

Solar and Stellar Astrophysics · Physics 2015-05-28 Patrick Antolin , Erwin Verwichte

All theories that attempt to explain the heating of the high temperature plasma observed in the solar corona are based on short bursts of energy. The intensities and velocities measured in the cores of quiescent active regions, however, can…

Solar and Stellar Astrophysics · Physics 2015-06-05 Fana M. Mulu-Moore , Amy R. Winebarger , Harry P. Warren

Loops are fundamental structures in the magnetized atmosphere of the sun. Their physical properties are crucial for understanding the nature of the solar atmosphere. Transition region loops are relatively dynamic and their physical…

Solar and Stellar Astrophysics · Physics 2024-04-16 Shiyu Liang , Ziyuan Wang , Zhenghua Huang , Hengyuan Wei , Hui Fu , Ming Xiong , Lidong Xia

Our knowledge of the diffuse emission that encompasses active regions is very limited. In the present paper we investigate two off-limb active regions, namely AR10939 and AR10961, to probe the underlying heating mechanisms. For this purpose…

Solar and Stellar Astrophysics · Physics 2015-06-22 Srividya Subramanian , Durgesh Tripathi , James A. Klimchuk , Helen E. Mason

Active region 10961 was observed over a five day period (2007 July 2-6) by instrumentation on-board STEREO, Hinode, TRACE and SOHO. As it progressed from Sun centre to the solar limb a comprehensive analysis of the EUV, X-ray and magnetic…

Astrophysics · Physics 2009-09-24 Jane B. Noglik , Robert W. Walsh , Rhona C. Maclean