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Related papers: A Model of the Double Magnetic Cycle of the Sun

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Solar-cycle related variation of differential rotation is investigated through analyzing the rotation rates of magnetic fields, distributed along latitudes and varying with time at the time interval of August 1976 to April 2008. More…

Solar and Stellar Astrophysics · Physics 2015-06-16 K. J. Li , X. J. Shi , J. L. Xie , P. X. Gao , H. F. Liang , L. S. Zhan , W. Feng

We applied the method of continuous wavelet-transform to the time-frequency analysis to the sets of observations of relative sunspot numbers, sunspot areas and to 6 Mount Wilson HK-project stars with well-defined magnetic cycles. Wavelet…

Solar and Stellar Astrophysics · Physics 2016-09-20 E. A. Bruevich , V. V. Bruevich , B. P. Artamonov

The small-scale magnetic field is ubiquitous at the solar surface---even at high latitudes. From observations we know that this field is uncorrelated (or perhaps even weakly anticorrelated) with the global sunspot cycle. Our aim is to…

Solar and Stellar Astrophysics · Physics 2016-01-11 Bidya Binay Karak , Axel Brandenburg

Many stars exhibit strong magnetic fields, some of which are thought to be of primordial origin and others a sign of magnetic dynamo processes. We briefly review the results of observational studies of solar-type stars seeking to evaluate…

Astrophysics · Physics 2007-05-23 Allan Sacha Brun

The periods of magnetic activity cycles in the Sun and solar-type stars do not exhibit a simple or even single trend with respect to rotation rate or luminosity. Dynamo models can be used to interpret this diversity, and can ultimately help…

Solar and Stellar Astrophysics · Physics 2018-08-15 A. Strugarek , P. Beaudoin , P. Charbonneau , A. S. Brun

The Sun's magnetic field shows the 11-year solar cycle and shorter periodicities, popularly known as the quasi-biennial oscillations (QBOs) and Rieger-type periods, or ``season of the Sun." Although several theories have been proposed to…

Solar and Stellar Astrophysics · Physics 2025-10-28 Pawan Kumar , Belur Ravindra , Partha Chowdhury , Bidya Binay Karak

Aims. The Sun shows strong variability in its magnetic activity, from Grand minima to Grand maxima, but the nature of the variability is not fully understood, mostly because of the insufficient length of the directly observed solar activity…

Solar and Stellar Astrophysics · Physics 2014-02-24 I. G. Usoskin , G. Hulot , Y. Gallet , R. Roth , A. Licht , F. Joos , G. A. Kovaltsov , E. Thebault , A. Khokhlov

Having advanced knowledge of solar activity is important because the Sun's magnetic output governs space weather and impacts technologies reliant on space. However, the irregular nature of the solar cycle makes solar activity predictions a…

Solar and Stellar Astrophysics · Physics 2013-12-31 Dibyendu Nandy , Bidya Binay Karak

Solar supergranulation plays an important role in generating and structuring the solar magnetic field and as a mechanism responsible for the 11-year solar cycle. It is clearly detected within SOHO/MDI Dopplergrams, from which a variety of…

Solar and Stellar Astrophysics · Physics 2010-04-07 P. E. Williams , W. D. Pesnell

The Sun shows a wide range of temporal variations, from a few seconds to decades and even centuries, broadly classified into two classes short-term and Long-term. The solar dynamo mechanism is believed to be responsible for these global…

Solar and Stellar Astrophysics · Physics 2023-02-21 Bibhuti Kumar Jha

The diagram of indices of coronal and chromospheric activity allowed us to reveal stars where solar-type activity appears and regular cycles are forming. Using new consideration of a relation between coronal activity and the rotation rate,…

Solar and Stellar Astrophysics · Physics 2015-08-06 M. M. Katsova , N. I. Bondar' , M. A. Livshits

We provide a synthesis model demonstrating the "fast dynamo" action of the Sun. The latter is essentially accomplished via two toroidal structures presumably formed in the tachocline and placed symmetrically with respect to the equatorial…

Space Physics · Physics 2017-08-03 D. V. Sarafopoulos

We explore effects of random non-axisymmetric perturbations of kinetic helicity (the $\alpha$ effect) and diffusive decay of bipolar magnetic regions on generation and evolution of large-scale non-axisymmetric magnetic fields on the Sun.…

Solar and Stellar Astrophysics · Physics 2018-11-28 V. V. Pipin , A. G. Kosovichev

We investigate the occurrence of the "extended solar cycle" (ESC) as it occurs in a host observational data spanning 140 years. Investigating coronal, chromospheric, photospheric and interior diagnostics we develop a consistent picture of…

We study the time variations of the cycles of 20 active stars based on decades-long photometric or spectroscopic observations. A method of time-frequency analysis, as discussed in a companion paper, is applied to the data. Fifteen stars…

Solar and Stellar Astrophysics · Physics 2015-05-13 K. Oláh , Z. Kolláth , T. Granzer , K. G. Strassmeier , A. F. Lanza , S. Järvinen , H. Korhonen , S. L. Baliunas , W. Soon , S. Messina , G. Cutispoto

One peculiar feature of the solar cycle which is yet to be understood properly is the frequent occurrence of double peaks (also known as the Gnevyshev peaks). Not only the double peaks but also multiple peaks and spikes are often observed…

Solar and Stellar Astrophysics · Physics 2018-10-11 Bidya Binay Karak , Sudip Mandal , Dipankar Banerjee

The steady-state gamma-ray emission from the Sun is thought to consist of two emission components due to interactions with Galactic cosmic rays: (1) a hadronic disk component, and (2) a leptonic extended component peaking at the solar edge…

High Energy Astrophysical Phenomena · Physics 2025-08-11 A. Acharyya , A. Adelfio , M. Ajello , L. Baldini , C. Bartolini , D. Bastieri , J. Becerra Gonzalez , R. Bellazzini , B. Berenji , E. Bissaldi , R. D. Blandford , R. Bonino , E. Bottacini , S. Buson , R. A. Cameron , P. A. Caraveo , F. Casaburo , F. Casini , E. Cavazzuti , D. Cerasole , S. Ciprini , G. Cozzolongo , P. Cristarella Orestano , A. Cuoco , S. Cutini , F. D'Ammando , D. Depalo , S. W. Digel , N. Di Lalla , L. Di Venere , A. Domínguez , A. Fiori , Y. Fukazawa , P. Fusco , F. Gargano , C. Gasbarra , D. Gasparrini , S. Germani , F. Giacchino , N. Giglietto , F. Giordano , M. Giroletti , S. Guiriec , R. Gupta , M. Hashizume , E. Hays , J. W. Hewitt , A. Holzmann Airasca , D. Horan , X. Hou , T. Kayanoki , M. Kuss , S. Larsson , A. Laviron , J. Li , I. Liodakis , F. Longo , F. Loparco , S. López Pérez , M. N. Lovellette , P. Lubrano , S. Maldera , A. Manfreda , G. Martí-Devesa , R. Martinelli , M. N. Mazziotta , J. E. McEnery , I. Mereu , M. Michailidis , P. F. Michelson , N. Mirabal , T. Mizuno , P. Monti-Guarnieri , M. E. Monzani , A. Morselli , I. V. Moskalenko , N. Omodei , E. Orlando , J. F. Ormes , D. Paneque , M. Persic , M. Pesce-Rollins , V. Petrosian , R. Pillera , G. Principe , S. Rainò , R. Rando , B. Rani , M. Razzano , A. Reimer , O. Reimer , M. Sánchez-Conde , P. M. Saz Parkinson , D. Serini , C. Sgrò , E. J. Siskind , P. Spinelli , D. Tak , L. Tibaldo , D. F. Torres , J. Valverde , Z. Wadiasingh , W. Zhang

Observations of magnetic activity cycles in other stars provide a broader context for our understanding of the 11-year sunspot cycle. The discovery of short activity cycles in a few stars, and the recognition of analogous variability in the…

Solar and Stellar Astrophysics · Physics 2015-06-17 Travis S. Metcalfe

Magnetic activity is a global property of the Sun; the complex processes of solar activity are connected with the solar magnetic fields. For solar-type stars and the Sun magnetic activity depends on the physical parameters of the star. In…

Solar and Stellar Astrophysics · Physics 2013-06-17 E. A. Bruevich , I. K Rozgacheva

Solar inter-network magnetic field is the weakest component of solar magnetism, but contributes most of the solar surface magnetic flux. The study on its origin has been constrained by the inadequate tempo-spatial resolution and sensitivity…

Solar and Stellar Astrophysics · Physics 2015-05-26 Chunlan Jin , Jingxiu Wang