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Related papers: Bayesian rotation inversion of KIC 11145123

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We define the star transform as a generalization of the broken ray transform introduced by us in previous work. The advantages of using the star transform include the possibility to reconstruct the absorption and the scattering coefficients…

Mathematical Physics · Physics 2015-01-13 Fan Zhao , John C. Schotland , Vadim A. Markel

The non-uniform surface temperature distribution of rotating active stars is routinely mapped with the Doppler Imaging technique. Inhomogeneities in the surface produce features in high-resolution spectroscopic observations that shift in…

Instrumentation and Methods for Astrophysics · Physics 2022-02-23 A. Asensio Ramos , C. Diaz Baso , O. Kochukhov

We present the results of three-dimensional simulations of the deep convective envelope of a young (10 Myr) one-solar-mass star, obtained with the Anelastic Spherical Harmonic code. Since young stars are known to be faster rotators than…

Astrophysics · Physics 2008-04-03 Jérôme Ballot , Allan Sacha Brun , Sylvaine Turck-Chièze

Thanks to the asteroseimic study of the red giant star KIC 7341231 observed by Kepler, it has been possible to infer its radial differential rotation profile (Deheuvels et al. 2012). This opens new ways to constrain the physical mechanisms…

Solar and Stellar Astrophysics · Physics 2012-12-10 T. Ceillier , P. Eggenberger , R. A. García , S. Mathis

It is possible to learn about the orientation of a star's rotation axis by combining measurements of the star's rotation velocity ($v$) and its projection onto our line of sight ($v\sin i$). This idea has found many applications, including…

Instrumentation and Methods for Astrophysics · Physics 2020-02-19 Kento Masuda , Joshua N. Winn

Characterizing statistical properties of solutions of inverse problems is essential for decision making. Bayesian inversion offers a tractable framework for this purpose, but current approaches are computationally unfeasible for most…

Machine Learning · Statistics 2024-12-18 Jonas Adler , Ozan Öktem

Be stars are found to rotate close to their critical rotation and therefore they are considered as an important laboratory of study for stellar rotation. In this context, we obtain the projected rotational velocity of a sample of classical…

Solar and Stellar Astrophysics · Physics 2022-01-28 Martín Solar , Catalina Arcos , Michel Curé , Ronaldo S. Levenhagen , Ignacio Araya

Understanding differential rotation of Sun-like stars is of great importance for insight into the angular momentum transport in these stars. One means of gaining such information is that of asteroseismology. By a forward modeling approach…

Solar and Stellar Astrophysics · Physics 2016-02-22 Mikkel N. Lund , Mark S. Miesch , Jørgen Christensen-Dalsgaard

Rotationally-induced mode splitting frequencies of low-luminosity subgiants suggest that angular momentum transport mechanisms are 1-2 orders of magnitude more efficient in these stars than predicted by theory. Constraints on the rotation…

Solar and Stellar Astrophysics · Physics 2023-05-03 T. Wilson , A. R. Casey , I. Mandel , W. H. Ball , E. Bellinger , G. Davies

We have derived the mean broadening profile of the star V102 in the region of the open cluster IC4665 from high resolution spectroscopy. At a projected equatorial rotation velocity of vsini = (105 +- 12)km/s we find strong deviation from…

Astrophysics · Physics 2009-11-10 A. Reiners , M. Huensch , M. Hempel , J. H. M. M. Schmitt

In this paper we demonstrate a computational method to solve the inverse scattering problem for a star-shaped, smooth, penetrable obstacle in 2D. Our method is based on classical ideas from computational geometry. First, we approximate the…

The evolutionary status of Be-type stars remains unclear, with both single-star and binary pathways having been proposed. Here, VFTS spectroscopy of 73 Be-type stars, in the spectral-type range, B0--B3, is analysed to estimate projected…

Solar and Stellar Astrophysics · Physics 2022-03-14 P. L. Dufton , D. J. Lennon , J. I. Villasenor , I. D. Howarth , C. J. Evans , S. E. de Mink , H. Sana , W. D. Taylor

Stokes inversion techniques are very powerful methods for obtaining information on the thermodynamic and magnetic properties of solar and stellar atmospheres. In recent years, very sophisticated inversion codes have been developed that are…

Solar and Stellar Astrophysics · Physics 2022-03-23 C. J. Díaz Baso , A. Asensio Ramos , J. de la Cruz Rodríguez

We have acquired high-resolution optical spectroscopy for a sample of T Tauri stars (TTSs) in open clusters using Hydra on the WIYN 3.5m telescope, and present projected rotational velocities (v sin i values) for 54 stars in IC 5070 and 99…

Solar and Stellar Astrophysics · Physics 2026-01-14 Laurin M. Gray , Katherine L. Rhode , Luisa M. Rebull

In this paper, we report the potential detection of a nonmonotonic radial rotation profile in a low-mass lower-luminosity giant star. For most low- and intermediate-mass stars, the rotation on the main sequence seems to be close to rigid.…

We continue our studies on stellar latitudinal differential rotation. The presented work is a sequel of the work of Reiners et al. who studied the spectral line broadening profile of hundreds of stars of spectral types A through G at high…

Solar and Stellar Astrophysics · Physics 2010-10-29 Matthias~Ammler von Eiff , Ansgar Reiners

We extend so-called slit-slide-sew bijections to constellations and quasiconstellations. We present an involution on the set of hypermaps given with an orientation, one distinguished corner, and one distinguished edge leading away from the…

Combinatorics · Mathematics 2025-12-08 Jérémie Bettinelli , Dimitri Korkotashvili

Differential rotation is central to a great many mysteries in stars and planets. In Part I we predicted the order of magnitude and scaling of the differential rotation in both hydrodynamic and magnetohydrodynamic convection zones. Our…

Solar and Stellar Astrophysics · Physics 2020-09-02 Adam S. Jermyn , Shashikumar M. Chitre , Pierre Lesaffre , Christopher A. Tout

The presence of dips in the gravito-inertial modes period-spacing pattern of gamma-Dor stars is now well established by recent asteroseismic studies. Such Lorentzian-shaped inertial dips arise from the interaction of gravito-inertial modes…

Solar and Stellar Astrophysics · Physics 2024-10-30 Lucas Barrault , Stéphane Mathis , Lisa Bugnet

KIC 10685175 (TIC 264509538) was discovered to be a rapidly oscillating Ap star from {\it Kepler} long cadence data using super-Nyquist frequency analysis. It was re-observed by TESS with 2-min cadence data in Sectors 14 and 15. We analyzed…

Solar and Stellar Astrophysics · Physics 2020-08-14 Fangfei Shi , Donald Kurtz , Hideyuki Saio , Jianning Fu , Huawei Zhang