Magnetic activity, differential rotation, and dynamo action in the pulsating F9IV star KIC 5955122

被引:10
作者
Bonanno, A. [1 ]
Froehlich, H. -E. [2 ]
Karoff, C. [3 ,4 ]
Lund, M. N. [3 ]
Corsaro, E. [1 ,5 ]
Frasca, A. [1 ]
机构
[1] Osserv Astrofis Catania, INAF, I-95123 Catania, Italy
[2] Leibniz Inst Astrophys Potsdam AIP, D-14482 Potsdam, Germany
[3] Aarhus Univ, Dept Phys & Astron, Stellar Astrophys Ctr, DK-8000 Aarhus C, Denmark
[4] Aarhus Univ, Dept Geosci, DK-8000 Aarhus C, Denmark
[5] Katholieke Univ Leuven, Inst Sterrenkunde, B-3001 Leuven, Belgium
基金
欧洲研究理事会; 新加坡国家研究基金会;
关键词
starspots; stars: rotation; stars: magnetic field; magnetohydrodynamics (MHD); stars: individual: KIC 5955122 stars: activity; SUN-LIKE STAR; MERIDIONAL CIRCULATION; MAIN-SEQUENCE; SOLAR DYNAMO; KEPLER; MODEL; CONVECTION; CYCLE; ZONE; FLOW;
D O I
10.1051/0004-6361/201424371
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present photometric spot modeling of the nearly four-year long light-curve of the Kepler target KIC 5955122 in terms of persisting dark circular surface features. With a Bayesian technique, we produced a plausible surface map that shows dozens of small spots. After some artifacts are removed, the residuals are at +/- 0.16 mmag. The shortest rotational period found is P = 16.4 +/- 0.2 days. The equator-to-pole extrapolated differential rotation is 0.25 +/- 0.02 rad/d. The spots are roughly half as bright as the unperturbed stellar photosphere. Spot latitudes are restricted to the zone +/- 60 degrees latitude. There is no indication for any near-pole spots. In addition, the p-mode pulsations enabled us to determine the evolutionary status of the star, the extension of the convective zone, and its radius and mass. We discuss the possibility that the clear signature of active regions in the light curve of the F9IV star KIC 5955122 is produced by a flux-transport dynamo action at the base of the convection zone. In particular, we argue that this star has evolved from an active to a quiet status during the Q0-Q16 period of observation, and we predict, according to our dynamo model, that the characteristic activity cycle is of the order of the solar one.
引用
收藏
页数:9
相关论文
共 43 条
  • [11] Starspot activity and rotation of the planet-hosting star Kepler-17
    Bonomo, A. S.
    Lanza, A. F.
    [J]. ASTRONOMY & ASTROPHYSICS, 2012, 547
  • [12] Kepler Planet-Detection Mission: Introduction and First Results
    Borucki, William J.
    Koch, David
    Basri, Gibor
    Batalha, Natalie
    Brown, Timothy
    Caldwell, Douglas
    Caldwell, John
    Christensen-Dalsgaard, Jorgen
    Cochran, William D.
    DeVore, Edna
    Dunham, Edward W.
    Dupree, Andrea K.
    Gautier, Thomas N., III
    Geary, John C.
    Gilliland, Ronald
    Gould, Alan
    Howell, Steve B.
    Jenkins, Jon M.
    Kondo, Yoji
    Latham, David W.
    Marcy, Geoffrey W.
    Meibom, Soren
    Kjeldsen, Hans
    Lissauer, Jack J.
    Monet, David G.
    Morrison, David
    Sasselov, Dimitar
    Tarter, Jill
    Boss, Alan
    Brownlee, Don
    Owen, Toby
    Buzasi, Derek
    Charbonneau, David
    Doyle, Laurance
    Fortney, Jonathan
    Ford, Eric B.
    Holman, Matthew J.
    Seager, Sara
    Steffen, Jason H.
    Welsh, William F.
    Rowe, Jason
    Anderson, Howard
    Buchhave, Lars
    Ciardi, David
    Walkowicz, Lucianne
    Sherry, William
    Horch, Elliott
    Isaacson, Howard
    Everett, Mark E.
    Fischer, Debra
    [J]. SCIENCE, 2010, 327 (5968) : 977 - 980
  • [13] Accurate fundamental parameters and detailed abundance patterns from spectroscopy of 93 solar-type Kepler targets
    Bruntt, H.
    Basu, S.
    Smalley, B.
    Chaplin, W. J.
    Verner, G. A.
    Bedding, T. R.
    Catala, C.
    Gazzano, J. -C.
    Molenda-Zakowicz, J.
    Thygesen, A. O.
    Uytterhoeven, K.
    Hekker, S.
    Huber, D.
    Karoff, C.
    Mathur, S.
    Mosser, B.
    Appourchaux, T.
    Campante, T. L.
    Elsworth, Y.
    Garcia, R. A.
    Handberg, R.
    Metcalfe, T. S.
    Quirion, P. -O.
    Regulo, C.
    Roxburgh, I. W.
    Stello, D.
    Christensen-Dalsgaard, J.
    Kawaler, S. D.
    Kjeldsen, H.
    Morris, R. L.
    Quintana, E. V.
    Sanderfer, D. T.
    [J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2012, 423 (01) : 122 - 131
  • [14] Gravity and limb-darkening coefficients for the Kepler, CoRoT, Spitzer, uvby, UBVRIJHK, and Sloan photometric systems
    Claret, A.
    Bloemen, S.
    [J]. ASTRONOMY & ASTROPHYSICS, 2011, 529
  • [15] Flux-transport dynamos with α-effect from global instability of tachocline differential rotation:: A solution for magnetic parity selection in the Sun
    Dikpati, M
    Gilman, PA
    [J]. ASTROPHYSICAL JOURNAL, 2001, 559 (01) : 428 - 442
  • [16] Flux-Transport Solar Dynamos
    Dikpati, Mausumi
    Gilman, Peter A.
    [J]. SPACE SCIENCE REVIEWS, 2009, 144 (1-4) : 67 - 75
  • [18] Meridional motions and the angular momentum balance in the solar convection zone
    Durney, BR
    [J]. ASTROPHYSICAL JOURNAL, 2000, 528 (01) : 486 - 492
  • [19] FRANDSEN S, 2000, 3 MONS WORKSH SCI PR, P163
  • [20] Newly discovered active binaries in the RasTyc sample of stellar X-ray sources - I. Orbital and physical parameters of six new binaries
    Frasca, A.
    Guillout, P.
    Marilli, E.
    Ferrero, R. Freire
    Biazzo, K.
    Klutsch, A.
    [J]. ASTRONOMY & ASTROPHYSICS, 2006, 454 (01) : 301 - 309