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Unstable states of the solar coronal magnetic field structure result in various flare behaviors. In this study, we compared the confined and eruptive flares that occurred under similar magnetic circumstances in the active region 12673, on…

Solar and Stellar Astrophysics · Physics 2025-03-24 Kouhei Teraoka , Daiki Yamasaki , Yusuke Kawabata , Shinsuke Imada , Toshifumi Shimizu

Solar flare emissions at Halpha and EUV/UV wavelengths often appear in the form of two ribbons, which has been regarded as evidence for a typical configuration of solar magnetic reconnection. However, such a ribbon structure has rarely been…

Astrophysics · Physics 2009-11-13 Chang Liu , Jeongwoo Lee , Dale E. Gary , Haimin Wang

We report on observation of the unusual kind of solar microflares, presumably associated with the so-called "topological trigger" of magnetic reconnection, which was theoretically suggested long time ago by Gorbachev et al. (Sov. Ast. 1988,…

Solar and Stellar Astrophysics · Physics 2017-11-15 Yurii V. Dumin , Boris V. Somov

Solar eruptive events such as coronal mass ejections and eruptive flares are frequently associated with the emergence of magnetic flux from the convection zone into the corona. We use three dimensional magnetohydrodynamic numerical…

Solar and Stellar Astrophysics · Physics 2022-07-27 James Leake , Mark Linton , Spiro Antiochos

The eruptions of solar filaments often show rotational motion about their rising direction, but it remains elusive what mechanism governs such rotation and how the rotation is related to the initial morphology of the pre-eruptive filament…

Solar and Stellar Astrophysics · Physics 2022-03-14 Zhenjun Zhou , Chaowei Jiang , Rui Liu , Yuming Wang , Lijuan Liu , Jun Cui

We analyze the magnetic evolution of solar active region (AR) NOAA 11476 that, between 9 and 10 May 2012, produced a series of surge-type eruptions accompanied by GOES X-ray class M flares. Using force-free models of the AR coronal…

Solar and Stellar Astrophysics · Physics 2024-04-17 Marcelo López Fuentes , Mariano Poisson , Cristina H. Mandrini

Solar magnetized "tornadoes", a phenomenon discovered in the solar atmosphere, appear as tornado-like structures in the corona but root in the photosphere. Like other solar phenomena, solar tornadoes are a feature of magnetized plasma and…

Solar and Stellar Astrophysics · Physics 2015-06-05 Yang Su , Tongjiang Wang , Astrid Veronig , Manuela Temmer , Weiqun Gan

Solar flares occur due to the sudden release of energy stored in active-region magnetic fields. To date, the pre-cursors to flaring are still not fully understood, although there is evidence that flaring is related to changes in the…

Solar and Stellar Astrophysics · Physics 2012-02-01 Sophie A. Murray , D. Shaun Bloomfield , Peter T. Gallagher

We report evolution of an atypical X-shaped flare ribbon which provides novel observational evidence of three-dimensional (3D) magnetic reconnection at a separator. The flare occurred on 2014 November 9. High-resolution slit-jaw 1330 A…

Solar and Stellar Astrophysics · Physics 2016-05-25 Y. Li , J. Qiu , D. W. Longcope , M. D. Ding , K. Yang

Sympathetic solar flares are eruptions that occur nearby in space and time, driven by an apparent interaction between the active regions in which they are triggered. Their statistical existence on the Sun has yet to be firmly established.…

Solar and Stellar Astrophysics · Physics 2025-02-05 Louis-Simon Guité , Antoine Strugarek , Paul Charbonneau

We have simulated the 3D emergence and interaction of two twisted flux tubes, which rise from the interior into the outer atmosphere of the Sun. We present evidence for the multiple formation and eruption of flux ropes inside the emerging…

Astrophysics · Physics 2009-11-13 V. Archontis , A. W. Hood

Solar flare emissions in the chromosphere often appear as elongated ribbons on both sides of the magnetic polarity inversion line (PIL), which has been regarded as evidence of a typical configuration of magnetic reconnection. However,…

Solar and Stellar Astrophysics · Physics 2015-06-05 Haimin Wang , Chang Liu

On 2024 May 6, Active Region 13663 produced an X4.5-class flare associated with a filament eruption that exhibited remarkable rotation and deflection dynamics. This study aims to investigate two key aspects of this event: the formation…

Solar and Stellar Astrophysics · Physics 2026-04-28 Xiaomeng Zhang , Jinhan Guo , Yang Guo , Mingde Ding , Brigitte Schmieder

Magnetic flux ropes (FRs) are twisted structures appearing on the sun, predominantly in the magnetically concentrated regions. These structures appear as coronal features known as filaments or prominences in H$\alpha$ observations, and as…

Solar and Stellar Astrophysics · Physics 2024-10-04 P. Vemareddy

Solar active region 11283 produced an X2.1 flare associated with a solar eruption on September 6, 2011. Observations revealed a preflare sigmoidal structure and a circular flare ribbon surrounding the typical two ribbon structure, along…

Solar and Stellar Astrophysics · Physics 2025-11-19 Arpita Roddanavar , Satoshi Inoue , Keiji Hayashi , Ju Jing , Wenda Cao , Haimin Wang

This Letter is to investigate the physics of a newly discovered phenomenon -- contracting flare loops in the early phase of solar flares. In classical flare models, which were constructed based on the phenomenon of expansion of flare loops,…

Astrophysics · Physics 2009-11-13 Jinhua Shen , Tuanhui Zhou , Haisheng Ji , Na Wang , Wenda Cao , Haimin Wang

Magnetic reconnection is a universal process that powers explosive energy release events such as solar flares, geomagnetic substorms, and some astrophysical jets. A characteristic feature of magnetic reconnection is the production of fast…

Solar and Stellar Astrophysics · Physics 2022-02-15 Chengcai Shen , Bin Chen , Katharine K. Reeves , Sijie Yu , Vanessa Polito , Xiaoyan Xie

We present observations and a magnetic-reconnection scenario of a twin pair of "atypical flares" that occurred on 2022 April 22 in a quadrupolar magnetic configuration formed by two active regions. The spatio-temporal evolution of the two…

Solar and Stellar Astrophysics · Physics 2026-03-04 Satyam Agarwal , Alphonse C. Sterling , Shibu K. Mathew , Ronald L. Moore , Qiang Hu , Ramit Bhattacharyya

Three-dimensional magnetic topology is crucial to understanding the explosive release of magnetic energy in the corona during solar flares. Much attention has been given to the pre-flare magnetic topology to identify candidate sites of…

Solar and Stellar Astrophysics · Physics 2018-12-12 Chaowei Jiang , Peng Zou , Xueshang Feng , Qiang Hu , Rui Liu , P. Vemareddy , Aiying Duan , Pingbing Zuo , Yi Wang , Fengsi Wei

We study the energy release process of a set of 51 flares (32 confined, 19 eruptive) ranging from GOES class B3 to X17. We use H$\alpha$ filtergrams from Kanzelh\"ohe Observatory together with SDO HMI and SOHO MDI magnetograms to derive…

Solar and Stellar Astrophysics · Physics 2018-02-07 Johannes Tschernitz , Astrid M. Veronig , Julia K. Thalmann , Jürgen Hinterreiter , Werner Pötzi