English
Related papers

Related papers: Sharp-Lined and Slowly Rotating Ap Stars

200 papers

We consider combined rotational, magnetic, and thermal evolution of the neutron star during the accretion phase in a binary system. A rapid accretion-driven decay of the magnetic field decreases substantially the efficiency of angular…

High Energy Astrophysical Phenomena · Physics 2015-07-14 Alfio Bonanno , Vadim Urpin

The spin-down of Be stars due to angular momentum transport from star to disc has been considered. This has been prompted by empirical studies of observed optical and IR line profile studies indicating that the disc is rotating in a…

Astrophysics · Physics 2007-05-23 John M. Porter

Models of rapidly rotating massive stars at low metallicities show significantly different evolution and higher metal yields compared to non-rotating stars. We estimate the spin-down time-scale of rapid rotating non-convective stars…

Solar and Stellar Astrophysics · Physics 2015-05-27 Herbert Ho Bun Lau , Adrian T. Potter , Christopher A. Tout

In previous work we identified six Sun-like stars observed by Kepler with exceptionally clear asteroseismic signatures of rotation. Here, we show that five of these stars exhibit surface variability suitable for measuring rotation. In order…

Solar and Stellar Astrophysics · Physics 2015-10-07 M. B. Nielsen , H. Schunker , L. Gizon , W. H. Ball

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

Today, one of the greatest challenges concerning the Ap/Bp stars is to understand the origin of their slow rotation and their magnetic fields. The favoured hypothesis for the latter is the fossil field, which implies that the magnetic…

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

Stellar rotation significantly shapes the evolution of massive stars, yet the interplay of mass and metallicity remains elusive, limiting our capacity to construct accurate stellar evolution models and to better estimate the impact of…

Solar and Stellar Astrophysics · Physics 2024-09-11 Weijia Sun , Cristina Chiappini

The Anomalous X-ray Pulsars (AXPs) are a small class of pulsars with spin periods in the 6-12 s range, very soft X-ray spectra, secular spin down on time scales of ~10^3-10^5 years, and lack of bright optical counterparts. Two, possibly…

Astrophysics · Physics 2007-05-23 S. Mereghetti , L. Chiarlone , G. L. Israel , L. Stella

In previous works of this series, we have shown that late B- and early A-type stars have genuine bimodal distributions of rotational velocities and that late A-type stars lack slow rotators. The distributions of the surface angular velocity…

Solar and Stellar Astrophysics · Physics 2015-06-03 J. Zorec , F. Royer

We examine the properties of $\sim50,000$ rotational variables from the ASAS-SN survey using distances, stellar properties, and probes of binarity from $\textit{Gaia}$ DR3 and the SDSS APOGEE survey. They have high amplitudes and span a…

Solar and Stellar Astrophysics · Physics 2023-05-18 Anya Phillips , C. S. Kochanek , Tharindu Jayasinghe , Lyra Cao , Collin T. Christy , D. M. Rowan , Marc Pinsonneault

We present a refined analysis of 15038 Kepler main sequence light curves to determine the stellar rotation periods. The initial period estimates come from an autocorrelation function, as has been done before. We then measure the duration of…

Solar and Stellar Astrophysics · Physics 2023-06-06 Joanne Tan , Gibor Basri

I review recent theoretical work on rapidly oscillating Ap stars and discuss key aspects of the physics of the oscillations observed in this class of pulsators.

Astrophysics · Physics 2009-11-13 M. S. Cunha

We rediscuss the evolutionary state of upper main sequence magnetic stars using a sample of Ap and Bp stars with accurate Hipparcos parallaxes and definitely determined longitudinal magnetic fields. FORS1 at the VLT in spectropolarimetric…

Astrophysics · Physics 2007-05-23 S. Hubrig , P. North , T. Szeifert

We re-discuss the evolutionary state of upper main sequence magnetic stars using a sample of Ap and Bp stars with accurate Hipparcos parallaxes and definitely determined longitudinal magnetic fields. We confirm our previous results obtained…

Astrophysics · Physics 2015-05-13 S. Hubrig , P. North , M. Schoeller

B-type stars are known to rotate at various velocities, including very fast rotators near the critical velocity as the Be stars. In this paper, we provide stellar models covering the mass range between 1.7 to 15 Msun, which includes the…

Solar and Stellar Astrophysics · Physics 2015-06-15 Cyril Georgy , Sylvia Ekström , Anahí Granada , Georges Meynet , Nami Mowlavi , Patrick Eggenberger , André Maeder

We present detailed analysis of the vertical pulsation mode cross-section in ten rapidly oscillating Ap (roAp) stars based on spectroscopic time-series observations. The aim of this analysis is to derive from observations a complete picture…

Astrophysics · Physics 2009-11-13 T. Ryabchikova , M. Sachkov , O. Kochukhov , D. Lyashko

The rotational and magnetic properties of many magnetic hot stars are poorly characterized, therefore the MiMeS and BinaMIcS collaborations have collected extensive high-dispersion spectropolarimetric datasets of these targets. We present…

Solar and Stellar Astrophysics · Physics 2018-01-24 M. E. Shultz , G. A. Wade , Th. Rivinius , C. Neiner , E. Alecian , D. Bohlender , D. Monin , J. Sikora , the MiMeS , BinaMIcS Collaborations

We study the rotational evolution of a protoneutron star with hyperons and nucleons or solely nucleons in its core due to the escape of the trapped neutrinos. It is found that at the early stage of its evolution, the stellar crust contracts…

Astrophysics · Physics 2007-05-23 Yefei Yuan , Jeremy S. Heyl

The results of long-term surveys of radial velocities of cool Ap and Am stars are presented. There are two samples, one of about 100 Ap stars and the other of 86 Am stars. Both have been observed with the CORAVEL scanner from Observatoire…

Astrophysics · Physics 2007-05-23 P. North , N. Ginestet , J. -M. Carquillat , F. Carrier , S. Udry