English
Related papers

Related papers: Reconstructing the Subsurface Three-Dimensional Ma…

200 papers

While the {\it Helioseismic and Magnetic Imager} (HMI) onboard the {\it Solar Dynamics Observatory} (SDO) provides Doppler velocity [$V$], continuum intensity [$I_C$], and line-depth [$Ld$] observations, each of which is sensitive to the…

Solar and Stellar Astrophysics · Physics 2015-09-24 Rachel Howe , Kiran Jain , Richard S. Bogart , Deborah A. Haber , Charles S. Baldner

Using the observations from Michelson Doppler Imager (MDI) onboard Solar and Heliospheric Observatory (SOHO), we develop a computational algorithm to automatically identify the bipolar magnetic regions (BMRs) in the active regions, and then…

Solar and Stellar Astrophysics · Physics 2017-05-10 Dong Li

In this study we report detailed observations of magnetic environment at four footpoints of two warm coronal loops observed on 5 May 2016 in NOAA AR 12542 (Loop I) and 17 Dec 2015 in NOAA AR 12470 (Loop II). These loops were connecting a…

Solar and Stellar Astrophysics · Physics 2019-03-29 Seray Şahin , Vasyl Yurchyshyn , Pankaj Kumar , Ali Kilcik , Kwangsu Ahn , Xu Yang

We analyze a three-dimensional (3D) magnetic structure and its stability in large solar active region(AR) 12192, using the 3D coronal magnetic field constructed under a nonlinear force-free field (NLFFF) approximation. In particular, we…

Solar and Stellar Astrophysics · Physics 2016-03-09 S. Inoue , K. Hayashi , K. Kusano

We use observations of line-of-sight magnetograms from Helioseismic and Magnetic Imager (HMI) on board of Solar Dynamics Observatory (SDO) to investigate polarity separation, magnetic flux, flux emergence rate, twist and tilt of solar…

Solar and Stellar Astrophysics · Physics 2019-02-20 A. S. Kutsenko , V. I. Abramenko , A. A. Pevtsov

We study five sequential solar flares (SOL2015-08-07) occurring in Active Region 12396 observed with the Goode Solar Telescope (GST) at the BBSO, complemented by IRIS and SDO observations. The main flaring region is an arch filament system…

Solar and Stellar Astrophysics · Physics 2018-03-19 Yingna Su , Rui Liu , Shangwei Li , Wenda Cao , Kwangsu Ahn , Haisheng Ji

Plasma upflows with a Doppler shift exceeding -10 km/s at active region (AR) boundaries are considered potential sources of the nascent slow solar wind. We investigate the driving mechanisms of a pair of coronal upflow regions on the…

Solar pores are active regions with large magnetic field strengths and apparent simple magnetic configurations. Their properties resemble the ones found for the sunspot umbra although pores do not show penumbra. Therefore, solar pores…

Solar and Stellar Astrophysics · Physics 2016-06-15 C. Quintero Noda , T. Shimizu , B. Ruiz Cobo , Y. Suematsu , Y. Katsukawa , K. Ichimoto

How eruption can recur from a confined magnetic structure is discussed based on the {\it Solar Dynamics Observatory} (SDO) observations of the NOAA active region 11444, which produced three eruptions within 1.5 hours on March 27, 2012. The…

Solar and Stellar Astrophysics · Physics 2017-08-15 Jeongwoo Lee , Chang Liu , Ju Jing , Jongchul Chae

We present a radiative magnetohydrodynamics simulation of the formation of an Active Region on the solar surface. The simulation models the rise of a buoyant magnetic flux bundle from a depth of 7.5 Mm in the convection zone up into the…

Solar and Stellar Astrophysics · Physics 2015-05-19 M. C. M. Cheung , M. Rempel , A. M. Title , M. Schüssler

In this Letter we present a seismological detection of a rising motion of magnetic flux in the shallow convection zone of the Sun, and show estimates of the emerging speed and its decelerating nature. In order to evaluate the speed of…

Solar and Stellar Astrophysics · Physics 2015-06-15 Shin Toriumi , Stathis Ilonidis , Takashi Sekii , Takaaki Yokoyama

The knowledge of magnetic topology is the key to understand magnetic energy release in astrophysics. Based on observed vector magnetograms, we have determined threedimensional (3D) topology skeleton of the magnetic fields in active region…

Astrophysics · Physics 2009-11-13 Hui Zhao , Jing-Xiu Wang , Jun Zhang , Chi-Jie Xiao , Hai-Min Wang

We studied the low-frequency $\lesssim 0.5\;$h$^{-1}$ (long-period $\gtrsim 2\;$h) oscillations of active regions (ARs). The investigation is based on an analysis of a time series built from Solar Dynamics Observatory/Helioseismic and…

Solar and Stellar Astrophysics · Physics 2022-03-22 G. Dumbadze , B. M. Shergelashvili , S. Poedts , T. V. Zaqarashvili , M. Khodachenko , P. De Causmaecker

Data for 3046 solar active regions (ARs) observed since May 12, 1996 to December 27, 2021 were utilized to explore how the magnetic fluxes from ARs of different complexity follow the solar cycle. Magnetograms from the Michelson Doppler…

Solar and Stellar Astrophysics · Physics 2022-12-15 Valentina I. Abramenko , Regina A. Suleymanova , Anastasija V. Zhukova

Context. The interplay between surface magnetic topology and chromospheric heating in active M dwarfs remains poorly constrained, limiting our understanding of their magnetic cycles and high-energy environments. Aims. We aim to test whether…

Solar and Stellar Astrophysics · Physics 2025-10-28 Shuai Liu , Jianrong Shi , Huigang Wei , Wenxian Li , Jifeng Liu , Shangbin Yang , Henggeng Han

Multiwavelength observations of the propagating disturbances (PDs), discovered by Atmospheric Imaging Assembly (AIA) onboard Solar Dynamics Observatory (SDO), are analyzed to determine its driving mechanism and physical nature. Two magnetic…

Adopting the thermal free-free emission mechanism, the coronal and chromospheric magnetic fields are derived from the polarization and spectral observations with the Nobeyama Radioheliograph at 1.76 cm. The solar active regions (AR) located…

Solar and Stellar Astrophysics · Physics 2018-02-14 A. Mouner , Abdelrazek M. K. Shaltout , M. M. Beheary , K. A. K. Gadallah , K. A. Edris

The complex dynamics that lead to the emergence of active regions on the sun are poorly understood. One possibility is that magnetic structures (flux tubes, etc.) rise from below the surface by self induction and convection that lead to the…

Solar and Stellar Astrophysics · Physics 2009-01-30 T. Hartlep , A. G. Kosovichev , J. Zhao , N. N. Mansour

The vector magnetic field characteristics of superactive regions (SARs) hold the key for understanding why SARs are extremely active and provide the guidance in space weather prediction. We aim to quantify the characteristics of SARs using…

Solar and Stellar Astrophysics · Physics 2015-06-05 A. Q. Chen , J. X. Wang

Solar active regions are where sunspots are located and photospheric magnetic fluxes are concentrated, therefore being the sources of energetic eruptions in the solar atmosphere. The detection and statistics of solar active regions have…

Solar and Stellar Astrophysics · Physics 2025-08-08 Jinhui Pan , Jiajia Liu , Shaofeng Fang , Rui Liu