English
Related papers

Related papers: Stellar differential rotation from direct starspot…

200 papers

We compute the differential rotation of main sequence stars of the spectral types F, G, K, and M by solving the equation of motion and the equation of convective heat transport in a mean-field formulation. For each spectral type the…

Astrophysics · Physics 2009-11-11 M. Kueker , G. Ruediger

Context. While rotation has a major impact on stellar structure and evolution, its effects are not well understood. Thanks to high- quality and long timebase photometric observations obtained with recent space missions, we are now able to…

The solar photosphere, chromosphere and corona are known to rotate differentially as a function of latitude. To date, it is unclear if the solar transition region also rotates differentially. In this paper, we investigate differential…

Solar and Stellar Astrophysics · Physics 2021-07-21 Jaidev Sharma , Brajesh Kumar , Anil K Malik , Hari Om Vats

The sunspot drawings of Johann Staudacher of 1749--1799 were used to determine the solar differential rotation in that period. These drawings of the full disk lack any indication of their orientation. We used a Bayesian estimator to obtain…

Solar and Stellar Astrophysics · Physics 2015-06-05 R. Arlt , H. -E. Froehlich

The characterization of solar surface differential rotation (SDR) from disk-integrated chromospheric measurements has important implications for the study of differential rotation and dynamo processes in other stars. Some chromospheric…

Solar and Stellar Astrophysics · Physics 2015-06-11 Luca Bertello , Alexei A. Pevtsov , A. Pietarila

The long-term, high precision photometry delivered by the Transiting Exoplanet Survey Satellite (TESS) enables us to gain new insight into known and hitherto well-studied stars. In this paper, we present the result of our TESS study of the…

Solar and Stellar Astrophysics · Physics 2021-01-04 P. Ioannidis , J. H. M. M. Schmitt

We present the results of numerical experiments to assess degeneracies in lightcurve models of starspots. Using synthetic lightcurves generated with the Cheetah starspot modeling code, we explore the extent to which photometric light curves…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Lucianne M. Walkowicz , Gibor S. Basri , Jeff A. Valenti

The aim of this paper is to study the latitudinal variation in the solar rotation in soft X-ray corona. The time series bins are formed on different latitude regions of the solar full disk (SFD) images that extend from 80 degree South to 80…

Solar and Stellar Astrophysics · Physics 2015-05-18 Satish Chandra , Hari Om Vats , K. N. Iyer

The present study reports the discovery of Sun-like stars, namely main-sequence stars with $T_{\rm eff}$, $\log g$ and rotation periods $P_{rot}$ similar to solar values, presenting evidence of surface differential rotation. An…

To explore the physics of large-scale flows in solar-like stars, we perform 3D anelastic simulations of rotating convection for global models with stratification resembling the solar interior. The numerical method is based on an implicit…

Solar and Stellar Astrophysics · Physics 2013-12-10 G. Guerrero , P. K. Smolarkiewicz , A. G. Kosovichev , N. N. Mansour

We report on a new method for tracking the phases of the orbital modulations in very short-period, near-contact, and contact binary systems systems in order to follow starspots. We apply this technique to Kepler light curves for 414 binary…

Solar and Stellar Astrophysics · Physics 2015-06-23 Bhaskaran Balaji , Bryce Croll , Alan M. Levine , Saul Rappaport

Quasi-periodic modulations of the stellar light curve may result from dark spots crossing the visible stellar disc. Due to differential rotation, spots at different latitudes generally have different rotation periods. Hence, by studying…

Solar and Stellar Astrophysics · Physics 2017-02-22 A. R. G. Santos , M. S. Cunha , P. P. Avelino , R. A. García , S. Mathur

Surface differential rotation (SDR) plays a key role in dynamo models. SDR estimates are therefore essential for constraining theoretical models. We measure a lower limit to SDR in a sample of solar-like stars belonging to young…

Solar and Stellar Astrophysics · Physics 2016-06-15 E. Distefano , A. C. Lanzafame , A. F. Lanza , S. Messina , F. Spada

Stellar spot distribution has consequences on the observable periodic signals in long-time baseline ground-based photometry. We model the statistics of the dominating spots of two young and active Solar-type stars, V889 Her and LQ Hya, in…

Solar and Stellar Astrophysics · Physics 2024-10-10 Mikko Tuomi , Jyri J. Lehtinen , Gregory W. Henry , Thomas Hackman

Long-lived rotational and meridional flows are important ingredients of the solar cycle. Magnetic field images have typically been used to measure these flows on the solar surface by cross-correlating thin longitudinal strips or square…

Solar and Stellar Astrophysics · Physics 2017-02-15 Derek A. Lamb

The differentially rotating outer layers of stars are thought to play a role in driving their magnetic activity, but the underlying mechanisms that generate and sustain differential rotation are poorly understood. We report the measurement…

Solar and Stellar Astrophysics · Physics 2018-09-24 O. Benomar , M. Bazot , M. B. Nielsen , L. Gizon , T. Sekii , M. Takata , H. Hotta , S. Hanasoge , K. R. Sreenivasan , J. Christensen-Dalsgaard

We present rotation periods for thousands of active stars in the Kepler field derived from Q3 data. In most cases a second period close to the rotation period was detected, which we interpreted as surface differential rotation (DR). Active…

Solar and Stellar Astrophysics · Physics 2015-06-16 Timo Reinhold , Ansgar Reiners , Gibor Basri

We present the results of a study of differential rotation on the K2 IV primary of the RS CVn binary II Pegasi (HD 224085) performed by inverting light curves to produce images of the dark starspots on its surface. The data were obtained in…

Solar and Stellar Astrophysics · Physics 2015-05-19 Rachael M. Roettenbacher , Robert O. Harmon , Nalin Vutisalchavakul , Gregory W. Henry

The main aim of this work is to determine the solar differential rotation by tracing sunspot groups during the period 1964-2016, using the Kanzelh\"ohe Observatory for Solar and Environmental Research (KSO) sunspot drawings and white light…

Context. Stars experience rapid contraction or expansion at different phases of their evolution. Modelling the angular momentum and chemical elements transport occurring during these phases remains an unsolved problem. Aims. We study a…

Solar and Stellar Astrophysics · Physics 2021-05-05 B. Gouhier , F. Lignières , L. Jouve