Dramatic changes in solar and stellar magnetic activity cycles – what drives them, and can we predict them?  Page description

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Details of project

  
Identifier
81421
Type K
Principal investigator Van Driel Gesztelyi, Lídia
Title in Hungarian Jelentős változások a Nap és más csillagok mágneses ciklusaiban – értjük-e okaikat és képesek vagyunk-e előrejelzésükre?
Title in English Dramatic changes in solar and stellar magnetic activity cycles – what drives them, and can we predict them?
Keywords in Hungarian Napaktivitás, csillag aktivitás, aktivitási ciklusok, mágneses tér
Keywords in English Solar activity, stellar activity, activity cycles, magnetic field
Discipline
Astronomy (Council of Physical Sciences)100 %
Ortelius classification: Astrophysics
Panel Physics 1
Department or equivalent Konkoly Thege Miklós Astronomical Institute (Research Centre for Astronomy and Earth Sciences)
Participants Forgácsné Dajka, Emese Zelmíra
Kolláth, Zoltán
Kővári, Zsolt
Kriskovics, Levente
Oláh, Katalin Ilona
Petrovay, Kristóf
Vida, Krisztián
Starting date 2010-02-01
Closing date 2014-07-31
Funding (in million HUF) 15.036
FTE (full time equivalent) 12.17
state closed project
Summary in Hungarian
A Nap jelenlegi hosszú és mély aktivitási minimuma jelentős figyelmet keltett, különösen, mivel az előrejelzéssel foglalkozók legtöbbjét is meglepte. Javasoljuk, hogy a 23. ciklus leszálló ágát és a 24-es aktivitási ciklus lassú emelkedését vizsgálva tanulmányozzuk az átmenetet az aktivitás Nagy Maximumából egy alacsony-aktivitású fázisba. Egyrészről esettanulmányokat kívánunk folytatni: megvizsgálni jelentős aktív vidékek és aktivitási fészkek hatását a poláris mágneses terek felépülésére, valamint ciklus-husszúságú statisztikai vizsgálatokat a korona lyukak és nyugodt protuberanciák fejlődése és pozíció valtozása jobb megértésére – mindkettő információt szolgáltat a poláris mágneses terek fejlődéséről és a nagyléptékű áramlásokról (pl. meridionális cirkuláció) a Napon. Napfizikai vizsgálatainkat kiegészitjük és összekapcsoljuk csillag-aktivitási ciklusok vizsgálatával. A különböző aktivitási jelenségek nagy változatosságot mutatnak különböző aktív csillagokon, azok fizikai tulajdonságaitól, mint rotációs ráta, tömeg, kor, függően. Javasoljuk a csillagok mágneses ciklusai és azok előrejelezhetősége tanulmányozását hosszú megfigyelési sorozatokból. Külön hangsúlyt fektetünk az ultrarövid periódusú aktív törpecsillagokra, a rétegdinamóhoz szükséges tömeghatár fölött és alatt. A dinamó típusa a kisebb tömegű csillagoknál ugyanis megváltozik. Színindex adatok felhasználásával tanulmányozzuk aktív vidékek fejlődését, azaz a folt és fáklya területek változását csillagokon. Szoftvereket fejlesztünk, melyek segítségével modellezhetők az aktív csillagok felszíni struktúrái, és differenciális rotácioja, fotometria és spektroszkópia felhasználásával. A Nap- és csillagaktivitási kutatások kölcsönösen sokat tanulhatnak egymástól – a célunk a szinergiájuk.
Summary
The presently ongoing extended and deep activity minimum of the Sun has attracted considerable attention, especially since it took many cycle forecasters by surprise. We propose to investigate the declining phase of cycle 23 and the slow rise of cycle 24 to find out how the transition from a Great Maximum to a lower-activity phase is taking place. We propose to carry out case-studies of the influence of outstanding active regions and activity complexes on the build-up of the polar fields as well as cycle-long statistical studies of coronal holes and quiescent filaments, which both provide information about the evolution of polar fields and large-scale (e.g. meridional) flows. We will complement and combine solar studies with the studies of stellar activity cycles. There is a great variety of active stars with different physical properties like rotational rate, mass, age. We plan to study the magnetic cycles and their predictability building up and using long-term observations. An emphasis is put on the ultrashort period active dwarfs above and below the mass limit of the solar-type dynamo. Using colour index data, we will study active region evolution (extent of spots and faculae) on stars. We develop software enabling us to recover surface structures and flow patterns (differential rotation) of active stars using photometric and spectroscopic data.
Solar and stellar cycle studies have a great deal of information to exchange for their mutual benefit – such a synergy is our goal.




 

Final report

  
Results in Hungarian
Pályázati programunkban különböző típusú aktív csillagok és a Nap mágneses eredetű változásait vizsgáltuk, melyek egy része ciklikus. A Nap viselkedése hatással van a földi életre, változásainak ismerete kozmikus környezetünk megismerésének kulcsa. Részletesen vizsgálható folyamatai paradigmaként szolgálnak a csillagaktivitás tanulmányozásához. A Nap 11-éves foltciklusához képest a gyorsan forgó aktív törpecsillagokon 1-3 éves ciklusokat, míg a lassabban forgó óriáscsillagokon több évtizedes ciklusokat találtunk. A forgási periódus és a foltciklus hosszának kapcsolata alapvető fontosságú a mágneses dinamó elmélet számára. A napciklus a nap tachoklínájában működő dinamó eredménye, melynek vastagságára kapott értékünk jó egyezést mutat a helioszeizmológia eredményeivel. A napfoltszámban az északi és déli félteke között mutatkozó aszimmetriát a két féltekén levő poláris terek különbégével magyaráztuk. A 23. napciklus volt a Modernkori Nagy Maximum utolsó ciklusa, amelyet az elmúlt száz év legmélyebb napaktivitás minimuma követett 2009-ben. A 24. ciklus az előzőnél 40%-kal alacsonyabb napfoltszámokat produkált. A napciklus átalakulásának időszakában a napaktivitás különféle megnyilvánulásait vizsgáltuk, melyek fontos eredményekkel szolgáltak a napaktivitás jelenségkörének átfogó értelmezéséhez.
Results in English
During the project we studied the variability of magnetic origin, which are partly cyclic, on different kinds of active stars and on the Sun. The behavior of the Sun influences the life on Earth, the knowledge of its changes is the key to explore our cosmic neighborhood. Its processes serve as paradigms in examining stellar activity. Comparing to the 11-year cycles of the Sun, we find 1-3 years long cycles on fast rotating active dwarfs, while on slower rotating giants we could reveal changes on decadal timescales. The relation between the rotational periods and length of spot cycles is of fundamental importance for magnetic dynamo theory. The solar cycle originates from a dynamo working in the tachocline. Our result of its thickness agrees well with results from helioseismology. We explain the hemispheric asymmetry of sunspot numbers by difference in polar magnetic fields. The 23th cycle was the last one of the modern Grand Solar Maximum, followed by the deepest minimum of the past century, in 2009. The 24th cycle produced 40% less spots than the previous cycle. During this transitory period of the solar cycle we investigated various manifestations of solar activity, and obtained important results for the overall understanding of key aspects of the solar activity cycle.
Full text https://www.otka-palyazat.hu/download.php?type=zarobeszamolo&projektid=81421
Decision
Yes





 

List of publications

  
Balázs, L. G.; Gyenge, N., Korsós, M. B., Baranyi, T., Forgács-Dajka, E., Ballai, I,: Statistical relationship between the succeeding solar flares detected by the RHESSI satellite, Monthly Notices of the Royal Astronomical Society, 441, 1157-1165., 2014
Ermolli, I., Shibasaki, K., Tlatov, A., van Driel-Gesztelyi, L.: Solar indices from the photosphere to the corona: measurements and underlying physics, Space Science Reviews, submitted, 2014
Pevtsov, A.A., Berger, M.A., Nindos, A., Norton, A.A., van Driel-Gesztelyi, L.: Magnetic helicity, tilt, and twist, Space Science Reviews, in press., 2014
Mandrini, C.H., Noevo, F.A., Vásquez, A.M., Démoulin, P., van Driel-Gesztelyi, L., Baker, D., Culhane, J.L., Christiani, G.D., Pick, M.: How can active region plasma escape into the solar wind from below a closed helmet streamer?, Solar Physics, in press., 2014
van Driel-Gesztelyi, L., Green, L.M.: Evolution of active regions, Living Reviews in Solar Physics, in press., 2014
Valori, G., Romano, P., Malanushenko, A., Ermolli, I., Giorgi, F., Steed, K., van Driel-Gesztelyi, L., Zuccarello, F., Malherbe, J.-M.: The evolution of force-free parameter and free magnetic energy in Active Region NOAA 10365, Solar Physics, submitted., 2014
Olah, K., Moor, A., Kovari, Zs., Granzer, T., Strassmeier, K.G., Kriskovics, L., Vida, K.: Magnitude-range brightness variations of overactive K-giants, Astronomy and Astrophysics, submitted, 2014
Kovari, Zs., Olah, K.: Observing dynamos in cool stars, Space Science Reviews, submitted, 2014
van Driel-Gesztelyi, L., Culhane, J., Baker, D., Demoulin, P., Mandrini, C., DeRosa, M., Rouillard, A., Opitz, A., Stenborg, G., Vourlidas, A., Brooks, D.: Magnetic Topology of Active Regions and Coronal Holes: Implications for Coronal Outflows and the Solar Wind, Solar Physics, Volume 281, Issue 1, pp.237-262, 2012
Vida, K., Kriskovics, L., Olah, K.: A quest for activity cycles in low-mass stars, Astron. Nachr. Vol. 334, p. 972, 2013
Vida, K., Olah, K.: Detecting activity cycles of late-type dwarfs in Kepler data, arXiv:1308.2641, 2013
Kovari, Z., Bartus, J., Kriskovics, L., Vida, K., Olah, K.: On the reliability of measuring differential rotation of spotted stars, arXiv:1309.0684, 2013
Kovari, Z., Kriskovics, L., Olah, K., Vida, K., Bartus, J., Strassmeier, K., Weber, M.: Surface differential rotation of IL Hya from time-series Doppler images, arXiv:1309.1378, 2013
Kriskovics, L., Kovari, Z., Vida, K., Olah, K.: Activity on a Li-rich giant: DI Psc revisited, arXiv:1310.4786, 2013
Olah, K., Moor, A., Granzer, T., Strassmeier, K.: Strange Active Giants in Close Binary Systems, Central European Astrophysical Bulletin, Vol. 37, p. 235, 2013
Vida, K., Kriskovics, L., Olah, K., Korhonen, H.: The Strange Close Binary V405 And: the Influence of Different Dynamos on the Components, Central European Astrophysical Bulletin, Vol. 37, p. 245, 2013
Rappaport, S. et al. (+ Olah, K., Vida, K.): M-dwarf Rapid Rotators and the Detection of Relatively Young Multiple M-Star Systems, Astrophysical Journal, 2014
Olah, K.: Stellar activity cycles from long-term data by robotic telescopes, Contributions of the Astronomical Observatory Skalnate Pleso, 2014
Vida, K., Pal, A., Meszaros, L., Csepany, G., Jasko, A., Mezo, G., Olah, K.: The Fly's Eye project. Sidereal tracking on a hexapod mount, http://cdsads.u-strasbg.fr/abs/2014CoSka..43..530V, 2014
Vida, K., Olah, K., Szabo, R.: Looking for activity cycles in late-type Kepler stars using time-frequency analysis, Monthly Notices of the Royal Astronomical Society, Volume 441, p.2744, 2014
Culhane, J. L., Brooks, D. H., van Driel-Gesztelyi, L., Démoulin, P., Baker, D., DeRosa, M. L., Mandrini, C. H., Zhao, L., Zurbuchen, T. H.: Tracking Solar Active Region Outflow Plasma from Its Source to the Near-Earth Environment, Solar Physics, 289, 3799-3816., 2014
Török, T., Kliem, B., Berger, M., Linton, M., Démoulin, P., van Driel-Gesztelyi, L.: The evolution of writhe in kink-unstable flux ropes and erupting filaments, Plasma Physics and Controlled Fusion, Volume 56, Issue 6, article id. 064012, 2014
van Driel-Gesztelyi, L.; Baker, D., Török, T., Pariat, E., Green, L.,Williams, D., Carlyle, J., Valori, G., Démoulin, Matthews, S., Kliem, B., Malherbe, J.: Magnetic reconnection driven by filament eruption in the 7 June 2011 event, Nature of Prominences and their role in Space Weather. Proc. International Astronomical Union, IAU Symposium 300, pp. 502-503, 2014
van Driel-Gesztelyi, L.; Baker, D., Török, T., Pariat, E., Green, L.,Williams, D., Carlyle, J., Valori, G., Démoulin, Kliem, B., Matthews, S., Malherbe, J.: Coronal Magnetic Reconnection Driven by CME Expansion---the 2011 June 7 Event, The Astrophysical Journal, Volume 788, Issue 1, article id. 85, 12 pp., 2014
Carlyle, J.; Williams, D.; van Driel-Gesztelyi, L.; Innes, D.; Hillier, A. \& Matthews, S.:: Investigating the Dynamics and Density Evolution of Returning Plasma Blobs from the 2011 June 7 Eruption, The Astrophysical Journal, 782, article id. 87, 8 pp., 2014
Gonzalez Hernandez, I.; Komm, R.; van Driel-Gesztelyi, L.; Baker, D.; Harra, L. \& Howe, R.:: Subsurface flows associated with non-Joy oriented active regions: a case study, Journal of Physics: Conference Series, Volume 440, Issue 1, article id. 012050, 2013
Baker, D.; Brooks, D.; Demoulin, P.; van Driel-Gesztelyi, L.; Green, L.; Steed, K. \& Carlyle, J.:: Plasma Composition in a Sigmoidal Anemone Active Region, The Astrophysical Journal, Volume 778, Issue 1, article id. 69, 8 pp., 2013
Williams, D., Baker, D., van Driel-Gesztelyi, L.: Mass Estimates of Rapidly Moving Prominence Material from High-cadence EUV Images, The Astrophysical Journal, 764, article id. 165, 10 pp., 2013
Williams, D., Baker, D., van Driel-Gesztelyi, L., Green, L.: Spectroscopic measurements of EUV ejecta in a CME: a high-blueshift trailing thread, Nature of Prominences and their role in Space Weather. Proc. International Astronomical Union, IAU Symposium 300, 464-465., 2014
Valori, G.; Török, T.; Temmer, M.; Veronig, A.; van Driel-Gesztelyi, L. \& Vrsnak, B.:: Initiation of Coronal Mass Ejections by Sunspot Rotation, Nature of Prominences and their role in Space Weather. Proc. International Astronomical Union, IAU Symposium 300, 201-208., 2014
Baker, D., Brooks, D., Démoulin, P., van Driel-Gesztelyi, L., Green, L., Steed, K., Carlyle, J.: FIP bias in a sigmoidal active region, Nature of Prominences and their role in Space Weather., 2014
Carlyle, J., Williams, D., van Driel-Gesztelyi, L., Innes, D.: Density evolution of in-falling prominence material from the 7th June 2011 CME, Nature of Prominences and their role in Space Weather. Proc. International Astronomical Union, IAU Symposium 300, 401-402., 2014
Petrie, G. J. D., Petrovay, K., Schatten, K.: Solar Polar Fields and the 22-Year Activity Cycle: Observations and Models, Space Science Reviews, Online First, DOI: 10.1007/s11214-014-0064-4, 2014
Nagy, M., Petrovay, K.: Oscillator models of the solar cycle and the Waldmeier effect, Astronomische Nachrichten, 334, 964-967., 2013
Karak, B.B., Petrovay, K.: On the Compatibility of a Flux Transport Dynamo with a Fast Tachocline Scenario, Solar Phys. 282, 321-334. doi: 10.1007/s11207-012-0153-z, 2013
Karak, B.B, Petrovay, K.: Flux Transport Dynamo coupled with a Fast Tachocline Scenario, Proceedings of IAU 294: Solar and Astrophysical Dynamos and Magnetic Activity, in press, 2013
Tian, C., Petrovay, K.: Structures in compressible magnetoconvection and the nature of umbral dots, Astron. Astrophys., in press, 2013
Marschalkó, G., Petrovay, K.: Turbulent magnetic energy spectrum and the cancellation function of solar photospheric magnetic fields, Astron. Nachr., submitted, 2013
Nagy, M., Petrovay, K.: Oscillator Models of the Solar Cycle and the Waldmeier Effect, Astron. Nachr., submitted., 2013
Kolláth, Z., Oláh, K., van Driel-Gesztelyi, L.: Parallels among the “music scores” of solar cycles, space weather and Earth’s climate, Comparative Magnetic Minima: Characterizing quiet times in the Sun and Stars, Proc. IAU, IAU Symposium 286, 423-426., 2012
Oláh, K., van Driel-Gesztelyi, L., Strassmeier, K. G.: Modulated stellar and solar cycles: parallels and differences, Comparative Magnetic Minima: Characterizing quiet times in the Sun and Stars, Proc. IAU, IAU Symp. 286, 279-285., 2012
Oláh, K., Kővári, Zs., Vida, K., Strassmeier, K. G.: Magnetic Activity of Two Similar Subgiants in Binaries with Very Different Mass Ratios: EI Eri and V711 Tau, From Interacting Binaries to Exoplanets: Essential Modeling Tools, Proc. IAU, M.T. Richards and I. Hubeny (eds), IAU Symp. 282, 478-479., 2012
Vida, K., Oláh, K., Kővári, Zs.: Modelling of an Eclipsing RS CVn Binary: V405, From Interacting Binaries to Exoplanets: Essential Modeling Tools, Proc. IAU, M.T. Richards and I. Hubeny (eds), IAU Symp. 282, 199-200., 2012
Kővári, Zs. Bartus, J., Kriskovics, L., Oláh, K., Vida, K., Ribárik, O., Strassmeier, K. G.: Differential Rotation in Two RS CVn Systems: σ Gem and ζ And, From Interacting Binaries to Exoplanets: Essential Modeling Tools, Proc. IAU, M.T. Richards and I. Hubeny (eds), IAU Symp. 282, 197-198., 2012
Jurcsik, J., Hajdu, G., Szeidl, B., Oláh, K., Kelemen, J., Sódor, Á., Saha, A., Mallick, P., Claver, J.: Long-term photometric monitoring of RR Lyrae stars in Messier 3, Mon. Not. R. Astron. Soc., 419, 2173-2194., 2012
Oláh, K., Moór, A., Strassmeier, K.G., Borkovits, T., Granzer, T.: Long-term photometry of three active red giants in close binary systems: V2253 Oph, IT Com, and IS Vir, Astron. Nachr., in press., 2013
Vinkó, J., Sárneczky, K., Takáts, K., Marion, G. H., Hegedüs, T., Bíró, I. B., Borkovits, T., Szegedi-Elek, E., Farkas, A., Klagyivik, P., Kiss, L. L., Kovács, T., Pál, A., Szakáts, R., Szalai, N., Szalai, T., Szatmáry, K., Szing, A., Vida, K., Wheeler, J. C.: Testing supernovae Ia distance measurement methods with SN 2011fe, Astron. Astrophys. 546, A12, 2012
Sódor, Á., Jurcsik, J., Molnár, L., Szeidl, B., Hurta, Zs., Bakos, G. Á., Hartman, J., Béky, B., Noyes, R. W., Sasselov, D., Mazeh, T., Bartus, J., Belucz, B., Hajdu, G., Kovári, Zs., Kun, E., Nagy, I., Posztobányi, K., Smitola, P., Vida, K.: First Results of the Konkoly Blazhko Survey II, Progress in Solar/Stellar Physics with Helio- and Asteroseismology. H. Shibahashi, M. Takata, A.E. Lynas-Gray (eds.), ASP Conf. Proc. 462, 228., 2012
Sakamoto, T., Troja, E., Aoki, K., Guiriec, S., Im, M., Leloudas, G., Malesani, D., Melandri, A., de Ugarte Postigo, A., Urata, Y., Xu, D., D’Avanzo, P., Gorosabel, J., Jeon, Y., Sanchez-Ramirez, R., Andersen, M. I., Bai, J., Barthelmy, S. D., Briggs, M. S., Foley, S., Fruchter, A. S., Fynbo, J. P. U., Gehrels, N., Huang, K., Jang, M., Kawai, N., Korhonen, H., Mao, J., Norris, J. P., Preece, R. D., Racusin, J. L., Thone, C. C., Vida, K., Zhao, X.: Identifying the Location in the Host Galaxy of the Short GRB 111117A with the Chandra Sub-arcsecond Position, Astrophys. J., in press., 2013
Vinkó, J., Takáts, K., Szalai, T., Marion, G. H., Wheeler, J. C., Sárneczky, K., Garnavich, P. M., Kelemen, J., Klagyivik, P., Pál, A., Szalai, N., Vida, K.: Improved distance determination to M 51 from supernovae 2011dh and 2005cs, Astron. Astrophys. 540, A93., 2012
Kővári, Zs., Korhonen, H., Kriskovics, L., Vida, K., Donati, J.-F., Le Coroller, H., Monnier, J. D., Pedretti, E., Petit, P.: Measuring differential rotation of the K-giant ζ Andromedae, Astron. Astrophys. 539, A50., 2012
Belucz, B., Forgács-Dajka, E., Dikpati M.: Exploring North-South asymmetry in a Babcock-Leighton dynamo, Astron. Nachr., sublitted, 2013
Szabó, Gy. M., Szabó, R., Benkő, J. M., Lehmann, H., Mező, Gy., Simon, A. E., Kővári, Zs., Hodosán, G., Regály, Z., and Kiss, L. L.: Asymmetric Transit Curves as Indication of Orbital Obliquity: Clues from the Brown Dwarf Companion in KOI-13, From Interacting Binaries to Exoplanets: Essential Modeling Tools, Proc. IAU, M.T. Richards and I. Hubeny (eds), IAU Symp. 282, 139-140., 2012
Kővári, Zs., Korhonen, H., Strassmeier, K. G., Weber, M., Kriskovics, L., and Savanov, I.: Doppler imaging of stellar surface structure - XXIV. The lithium-rich single K-giants DP Canum Venaticorum and DI Piscium, Astron. Astrophys. 51, A2., 2013
Kriskovics, L., Vida, K., Kővári, Zs., Garcia-Alvarez, D., Oláh, K.: Doppler imaging of the double-lined active binary V824 Ara, Astron. Nachr., submitted., 2013
Molnár, L., Kolláth, Z., Szabó;, R., and Plachy, E.: New results in RR Lyrae modeling: Convective cycles, additional modes and more, Astron. Nachr., 333, 950-953., 2012
Molnár, L., Kolláth, Z., Szabó;, R., Bryson, S., Kolenberg, K., Mullally, F., Thompson, S. E.: Nonlinear Asteroseismology of RR Lyrae, Astrophys. J. 757, L13., 2012
Molnár, L., Kolláth, Z., and Szabó, R.: Can turbulent convective variations drive the Blazhko cycle? Dynamical investigation of the Stothers idea, Mon. Not. R. Astron. Soc. 424, 31-37., 2012
van Driel-Gesztelyi, L., Culhane, J. L., Baker, D., Démoulin, P., Mandrini, C. H., DeRosa, M. L., Rouillard, A. P., Opitz, A., Stenborg, G., Vourlidas, A., Brooks, D. H.: Magnetic Topology of Active Regions and Coronal Holes: Implications for Coronal Outflows and the Solar Wind, Solar Phys. 281, 237-262., 2012
Vargas Domínguez, S., van Driel-Gesztelyi, L., Bellot Rubio, L. R.: Granular-Scale Elementary Flux Emergence Episodes in a Solar Active Region, Solar Phys. 278, 99-120, 2012
Vargas Domínguez, S., MacTaggart, D., Green, L., van Driel-Gesztelyi, L., and Hood, A. W.: On Signatures of Twisted Magnetic Flux Tube Emergence, Solar Phys., 2012
Valori, G., Green, L. M., Démoulin, P., Vargas Domínguez, S., van Driel-Gesztelyi, L., Wallace, A., Baker, D., and Fuhrmann, M.: Nonlinear Force-Free Extrapolation of Emerging Flux with a Global Twist and Serpentine Fine Structures, Solar Phys. 278, 73-97., 2012
Harra, L. K., Archontis, V., Pedram, E., Hood, A. W., Shelton, D. L., and van Driel-Gesztelyi, L.: The Creation of Outflowing Plasma in the Corona at Emerging Flux Regions: Comparing Observations and Simulations, Solar Phys. 278, 47-71., 2012
Baker, D., van Driel-Gesztelyi, L., and Green, L. M.: Forecasting a CME by Spectroscopic Precursor?, Solar Phys. 276, 219-239., 2012
Williams, D. R., Baker, D., and van Driel-Gesztelyi, L.: Mass Estimates of Rapidly Moving Prominence Material from High-cadence EUV Images, Astrophys. J. 764, 165., 2013
Démoulin, P., Baker, D., Mandrini, C. H., and van Driel-Gesztelyi, L.: The 3D Geometry of Active Region Upflows Deduced from Their Limb-to-Limb Evolution, Solar Phys. in press., 2013
Török, T., Temmer, M., Valori, G., Veronig, A.M., van Driel-Gesztelyi, L., and Vrsnak, B.: Initiation of coronal mass ejections by sunspot rotation, Solar Phys., submitted., 2013
Frasca, A., Biazzo, K., Kővári, Zs., Marilli, E., Çakırlı, Ö.: Photospheric and chromospheric activity on the young solar-type star HD 171488 (V889 Herculis), Astron. Astrophys. 518, A48., 2010
Korhonen, H., Vida, K., Husarik, M., Mahajan, S., Szczygieł, D., Oláh, K.: Photometric and spectroscopic observations of three rapidly rotating late-type stars: EY Dra, V374 Peg, and GSC 02038-00293, Astron. Nachr. 331, 8, p.772, 2010
Attrill, G.D.R., Harra, L.K., van Driel-Gesztelyi, L., Wills-Davey, M.J.: Revealing the fine structure of coronal dimmings and associated flows with Hinode/EIS, Solar Phys. 264, 119-147., 2010
Vida, K., Oláh, K., Kővári, Zs.: Surface Evolution in stable magnetic fields. The case of the fully convective dwarf V374 Peg, Proc. IAU Symp. No. 273: Physics of Sun and Star Spots, Cambridge Univ. Press, ed. Choudhary and Strassmeier, p. 460., 2011
Kővári Zs., Frasca A., Biazzo K., Vida K., Marilli E., Çakirli Ö.
: Differential rotation on the young solar analogue V889 Herculis, Proc. IAU Symp. No. 273: Physics of Sun and Star Spots, Cambridge Univ. Press, ed. Choudhary and Strassmeier, p. 121
., 2011
Luoni, M.L., Démoulin, P., Mandrini, C.~H., van Driel-Gesztelyi, L.: Twisted Flux Tube Emergence Evidenced in Longitudinal Magnetograms: Magnetic Tongues, Solar Phys., 270, 45-74., 2011
Li, C., Matthews, S.A., van Driel-Gesztelyi, L., Sun, J., Owen, C.J.: Coronal Jets, Magnetic Topologies, and the Production of Interplanetary Electron Streams, Astrophys. J., 735, 43., 2011
Strassmeier, K. G. Carroll, T. A. Weber, M. Granzer, T. Bartus, J. Oláh, K. Rice, J. B.: Binary-induced magnetic activity? Time-series echelle spectroscopy and photometry of HD 123351 = CZ CVn, Astron. Astrophys. 535, A98, 2011
Oláh, K.: Time series photometry and starspot properties (invited talk), in: Proc. IAU Symp. No. 273: Physics of Sun and Star Spots, 22-26 August 2010, Ventura, CA, USA, Cambridge Univ. Press, ed. Choudhary and Strassmeier, p. 104, 2011
Karak, B.B., Petrovay, K.: On the Compatibility of a Flux Transport Dynamo with a Fast Tachocline Scenario, Solar Physics, 282, 321-334. doi: 10.1007/s11207-012-0153-z, 2013
Karak, B.B, Petrovay, K.: Flux Transport Dynamo coupled with a Fast Tachocline Scenario, Proceedings of IAU 294: Solar and Astrophysical Dynamos and Magnetic Activity, 294, 427-428., 2013
Tian, C., Petrovay, K.: Structures in compressible magnetoconvection and the nature of umbral dots, Astron. Astrophys., 551, id.A92, 12 pp., 2013
Marschalkó, G., Petrovay, K.: Turbulent magnetic energy spectrum and the cancellation function of solar photospheric magnetic fields, Astron. Nachr., 334, 952-955., 2013
Oláh, K., Kővári, Zs., Vida, K., Strassmeier, K. G.: Magnetic Activity of Two Similar Subgiants in Binaries with Very Different Mass Ratios: EI Eri and V711 Tau, From Interacting Binaries to Exoplanets: Essential Modeling Tools, Proc. IAU, M.T. Richards and I. Hubeny (eds), IAU Symp. 282, 478-479., 2012
Kővári, Zs. Bartus, J., Kriskovics, L., Oláh, K., Vida, K., Ribárik, O., Strassmeier, K. G.: Differential Rotation in Two RS CVn Systems: σ Gem and ζ And, From Interacting Binaries to Exoplanets: Essential Modeling Tools, Proc. IAU, M.T. Richards and I. Hubeny (eds), IAU Symp. 282, 197-198., 2012
Oláh, K., Moór, A., Strassmeier, K.G., Borkovits, T., Granzer, T.: Long-term photometry of three active red giants in close binary systems: V2253 Oph, IT Com, and IS Vir, Astron. Nachr., Vol. 334, p. 625, 2013
Kővári, Zs., Korhonen, H., Kriskovics, L., Vida, K., Donati, J.-F., Le Coroller, H., Monnier, J. D., Pedretti, E., Petit, P.: Measuring differential rotation of the K-giant ζ Andromedae, Astron. Astrophys. 539, A50., 2012
Belucz, B., Forgács-Dajka, E., Dikpati M.: Exploring North-South asymmetry in a Babcock-Leighton dynamo, Astron. Nachr., 334, 960-963., 2013
Kővári, Zs., Korhonen, H., Strassmeier, K. G., Weber, M., Kriskovics, L., and Savanov, I.: Doppler imaging of stellar surface structure - XXIV. The lithium-rich single K-giants DP Canum Venaticorum and DI Piscium, Astron. Astrophys. 51, A2., 2013
Kriskovics, L., Vida, K., Kővári, Zs., Garcia-Alvarez, D., Oláh, K.: Doppler imaging of the double-lined active binary V824 Ara, Astron. Nachr. Vol. 334, p.976, 2013
van Driel-Gesztelyi, L., Culhane, J. L., Baker, D., Démoulin, P., Mandrini, C. H., DeRosa, M. L., Rouillard, A. P., Opitz, A., Stenborg, G., Vourlidas, A., Brooks, D. H.: Magnetic Topology of Active Regions and Coronal Holes: Implications for Coronal Outflows and the Solar Wind, Solar Physics, 281, 237-262., 2012
Vargas Domínguez, S., van Driel-Gesztelyi, L., Bellot Rubio, L. R.: Granular-Scale Elementary Flux Emergence Episodes in a Solar Active Region, Solar Physics, 278, 99-120., 2012
Vargas Domínguez, S., MacTaggart, D., Green, L., van Driel-Gesztelyi, L., and Hood, A. W.: On Signatures of Twisted Magnetic Flux Tube Emergence, Solar Physics, 278, 33-45., 2012
Valori, G., Green, L. M., Démoulin, P., Vargas Domínguez, S., van Driel-Gesztelyi, L., Wallace, A., Baker, D., and Fuhrmann, M.: Nonlinear Force-Free Extrapolation of Emerging Flux with a Global Twist and Serpentine Fine Structures, Solar Phys. 278, 73-97., 2012
Harra, L. K., Archontis, V., Pedram, E., Hood, A. W., Shelton, D. L., and van Driel-Gesztelyi, L.: The Creation of Outflowing Plasma in the Corona at Emerging Flux Regions: Comparing Observations and Simulations, Solar Phys. 278, 47-71., 2012
Baker, D., van Driel-Gesztelyi, L., and Green, L. M.: Forecasting a CME by Spectroscopic Precursor?, Solar Phys. 276, 219-239., 2012
Démoulin, P., Baker, D., Mandrini, C. H., and van Driel-Gesztelyi, L.: The 3D Geometry of Active Region Upflows Deduced from Their Limb-to-Limb Evolution, Solar Physics, 283, 341-367., 2013
Török, T., Temmer, M., Valori, G., Veronig, A.M., van Driel-Gesztelyi, L., and Vrsnak, B.: Initiation of coronal mass ejections by sunspot rotation, Solar Physics, 286, 453-477., 2013
Szabó, Gy. M., Kiss, L. L., Benkő, J.M., Mező, Gy., Nuspl, J., Regály, Zs., Sárneczky, K., Simon, A.E., Leto, G. Zanmar Sanchez, R., Ngeow, C.-C., Kővári, Zs., Szabó, R.: A multi-site campaign to detect the transit of the second planet in HAT-P-13, Astron. Astrophys. 523, A84, 2010
Frasca, A., Biazzo, K., Kővári, Zs., Marilli, E., Çakırlı, Ö.: Photospheric and chromospheric activity on the young solar-type star HD 171488 (V889 Herculis), Astron. Astrophys. 518, A48., 2010
Korhonen, H., Vida, K., Husarik, M., Mahajan, S., Szczygieł, D., Oláh, K.: Photometric and spectroscopic observations of three rapidly rotating late-type stars: EY Dra, V374 Peg, and GSC 02038-00293, Astron. Nachr. 331, 8, p.772, 2010
Ballai, I., and Forgács-Dajka, E.: The dynamical solar atmosphere, Journal of Physics: Conference Series, Volume 218, Issue 1, 012002, 2010
I. Ballai, E. Forgács-Dajka and M. Douglas: Magnetoacoustic surface gravity waves at a spherical interface, Astron. Astrophys. 527, A12, 2011
Attrill, G.D.R., Harra, L.K., van Driel-Gesztelyi, L., Wills-Davey, M.J.: Revealing the fine structure of coronal dimmings and associated flows with Hinode/EIS, Solar Phys. 264, 119-147., 2010
Vida, K., Oláh, K., Kővári, Zs.: Surface Evolution in stable magnetic fields. The case of the fully convective dwarf V374 Peg, Proc. IAU Symp. No. 273: Physics of Sun and Star Spots, Cambridge Univ. Press, ed. Choudhary and Strassmeier, p. 460., 2011
Szabó Gy.M., Szabó R., Benkő J.M., Lehmann H., Mező Gy., Simon A.E., Kővári Zs., Hodosán G., Regály Zs., Kiss L.L.: Asymmetric Transit Curves as Indication of Orbital Obliquity: Clues from the Late-type Dwarf Companion in KOI-13, Astrophys. J. Lett. 736, L.4., 2011
Kővári Zs., Frasca A., Biazzo K., Vida K., Marilli E., Çakirli Ö.
: Differential rotation on the young solar analogue V889 Herculis, Proc. IAU Symp. No. 273: Physics of Sun and Star Spots, Cambridge Univ. Press, ed. Choudhary and Strassmeier, p. 121
., 2011
Luoni, M.L., Démoulin, P., Mandrini, C.~H., van Driel-Gesztelyi, L.: Twisted Flux Tube Emergence Evidenced in Longitudinal Magnetograms: Magnetic Tongues, Solar Phys., 270, 45-74., 2011
Li, C., Matthews, S.A., van Driel-Gesztelyi, L., Sun, J., Owen, C.J.: Coronal Jets, Magnetic Topologies, and the Production of Interplanetary Electron Streams, Astrophys. J., 735, 43., 2011
Strassmeier, K. G. Carroll, T. A. Weber, M. Granzer, T. Bartus, J. Oláh, K. Rice, J. B.: Binary-induced magnetic activity? Time-series echelle spectroscopy and photometry of HD 123351 = CZ CVn, Astron. Astrophys. 535, A98, 2011
Oláh, K.: Time series photometry and starspot properties (invited talk), in: Proc. IAU Symp. No. 273: Physics of Sun and Star Spots, 22-26 August 2010, Ventura, CA, USA, Cambridge Univ. Press, ed. Choudhary and Strassmeier, p. 104, 2011




 

Events of the project

  
2012-04-05 16:34:20
Résztvevők változása
2012-01-04 06:48:32
Kutatóhely váltás
A kutatás helye megváltozott. Korábbi kutatóhely: (MTA Csillagászati és Földtudományi Kutatóközpont), Új kutatóhely: Konkoly Thege Miklós Csillagászati Intézet (MTA Csillagászati és Földtudományi Kutatóközpont).



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