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Related papers: Ap stars with variable periods

200 papers

Pulsational variability is observed in several types of main sequence stars with anomalous chemical abundances. In this contribution I summarize the relationship between pulsations and chemical peculiarities, giving special emphasis to…

Astrophysics · Physics 2015-05-13 O. Kochukhov

We present a comprehensive statistical investigation of the evolution of magnetic CP stars, aimed at providing constraints to the theories that deal with the origin of the magnetic field in these stars. We have collected from the literature…

Astrophysics · Physics 2009-11-11 O. Kochukhov , S. Bagnulo

We have proposed the new explanation of some magnetic chemically peculiar (MCP) stars anomalies, which is based on assumption that such stars can be the close binary systems with a secondary component being neutron star. Within this…

Astrophysics · Physics 2007-12-17 V. F. Gopka , O. M. Ulyanov , S. M. Andrievsky

Some Ap stars with strong magnetic fields pulsate in high order p-modes; they are called roAp (rapidly oscillating Ap) stars. The p-mode frequencies are modified by the magnetic fields. Although the large frequency separations are hardly…

Solar and Stellar Astrophysics · Physics 2015-06-17 Hideyuki Saio

We have analysed the photometric data obtained with the STEREO spacecraft for 558 non-magnetic chemically peculiar (CP) stars to search for rotational and pulsational variability. Applying the Lomb-Scargle and the phase dispersion…

Solar and Stellar Astrophysics · Physics 2015-06-12 E. Paunzen , K. T. Wraight , L. Fossati , M. Netopil , G. J. White , D. Bewsher

Stars of spectral classes A and late B are almost entirely radiative. CP stars are a slowly rotating subgroup of these stars. It is possible that they possessed long-lived accretion disks in their T Tauri phase. Magnetic coupling of disk…

Astrophysics · Physics 2009-11-07 Rainer Arlt , Rainer Hollerbach , Guenther Ruediger

Ap/Bp stars are magnetic chemically peculiar early A and late B type stars of the main sequence. They exhibit peculiar surface abundance anomalies that are thought to be the result of gravitational settling and radiative levitation. The…

Astrophysics · Physics 2007-05-23 S. Turcotte

Since the end of 2018, the Transiting Exoplanet Survey Satellite (TESS) provides high-quality space data on stellar photometry to the astronomical community. We present the results of an analysis of TESS photometric data for known slowly…

Chemically peculiar (CP) stars of the upper main sequence are characterised by specific anomalies in the photospheric abundances of some chemical elements. The group of CP2 stars, which encompasses classical Ap and Bp stars, exhibits…

The magnetic chemically peculiar (CP2) stars of the upper main sequence are well-suited for investigating the impact of magnetic fields on the surface layers of stars, which leads to abundance inhomogeneities (spots) resulting in…

Solar and Stellar Astrophysics · Physics 2015-12-15 K. Bernhard , S. Huemmerich , E. Paunzen

Magnetic chemically peculiar (mCP) stars exhibit complex atmospheres that allow the investigation of such diverse phenomena as atomic diffusion, magnetic fields, and stellar rotation. The advent of space-based photometry provides the…

Aims. In order to better model massive B-type stars, we need to understand the physical processes taking place in slowly pulsating B (SPB) stars, chemically peculiar Bp stars, and non-pulsating normal B stars co-existing in the same part of…

Astrophysics · Physics 2009-11-13 M. Briquet , S. Hubrig , P. De Cat , C. Aerts , P. North , M. Scholler

High-precision space-based photometry obtained by the \emph{Kepler} and \emph{TESS} missions has revealed evidence of rotational modulation associated with main sequence (MS) A and late-B type stars. Generally, such variability in these…

Solar and Stellar Astrophysics · Physics 2020-09-30 James Sikora , Gregg Wade , Jason Rowe

Magnetic fields on hot stars can produce a variety of interesting effects on the velocity, density, and temperature structure in the winds from the stars. The fields can produce a longitudinal dependence of the mass flux, which would lead…

Astrophysics · Physics 2007-05-23 Joseph P. Cassinelli

The upper main sequence stars CU Virginis is the most enigmatic object among magnetic chemically peculiar (mCP) stars. It is an unusually fast rotator showing strictly periodic light variations in all regions of the electromagnetic…

Solar and Stellar Astrophysics · Physics 2019-12-30 Zdeněk Mikulášek , Jiří Krtička , Andrzej Pigulski , Gregory W. Henry , Jan Janík

HD~63401 is known magnetic chemically peculiar (mCP) star that shows a slow rotation and probably possesses a hydrodynamically stable stellar atmosphere. In the latter case the atomic diffusion mechanism enforced by the magnetic field can…

Solar and Stellar Astrophysics · Physics 2020-03-09 Pavlo Kashko , Viktor Khalack , Oleksandr Kobzar , Dmytro Tvardovskyi , Mathieu Perron-Cormier

Ap star magnetism is often attributed to fossil magnetic fields which have not changed much since the pre-main-sequence epoch of the stars. Stable magnetic field configurations are known which could persist probably for the entire…

Solar and Stellar Astrophysics · Physics 2015-05-20 R. Arlt , G. Ruediger

Recently, high-precision optical 2~min cadence light curves obtained with \emph{TESS} for targets located in the mission's defined first four sectors have been released. The majority of these high-cadence and high-precision measurements…

Solar and Stellar Astrophysics · Physics 2019-06-26 J. Sikora , A. David-Uraz , S. Chowdhury , D. M. Bowman , G. A. Wade , V. Khalack , O. Kobzar , O. Kochukhov , C. Neiner , E. Paunzen

Context. The chemically peculiar (CP) stars of the upper main sequence are defined by spectral peculiarities that indicate unusual elemental abundance patterns in the presence of diffusion in the calm, stellar atmospheres. Some of them have…

We present the results of a systematic study of the magnetic fields and other properties of the Ap stars with resolved magnetically split lines. This study is based on new measurements of the mean magnetic field modulus, the mean…

Solar and Stellar Astrophysics · Physics 2017-04-26 G. Mathys