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相关论文: A search for rapid pulsations among 9 luminous Ap …

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With FORS1 at the VLT we have tried for the first time to measure the magnetic field variation over the pulsation cycle in six roAp stars to begin the study of how the magnetic field and pulsation interact. For the star HD101065, which has…

天体物理学 · 物理学 2009-11-10 S. Hubrig , D. W. Kurtz , S. Bagnulo , T. Szeifert , M. Schoeller , G. Mathys , W. A. Dziembowski

We present the analysis of spectroscopic time-series observations of the roAp star 10 Aql. Observations were carried out in July 2006 with the UVES and SARG spectrographs simultaneously with the MOST mini-satellite photometry. All these…

天体物理学 · 物理学 2010-11-26 M. Sachkov , O. Kochukhov , T. Ryabchikova , F. Leone , S. Bagnulo , W. W. Weiss

Among the A/B stars, about 5% host large-scale organised magnetic fields. These magnetic stars show also abundance anomalies in their spectra, and are therefore called the magnetic Ap/Bp stars. Most of these stars are also slow rotators…

We present the analysis of K2 short cadence data of the rapidly oscillating Ap (roAp) star, 33 Librae (HD 137949). The precision afforded to the K2 data allow us to identify at least 11 pulsation modes in this star, compared to the three…

太阳与恒星天体物理 · 物理学 2018-08-08 Daniel L. Holdsworth , Margarida S. Cunha , Hiromoto Shibahashi , Donald W. Kurtz , Dominic M. Bowman

HR 1217 is one of the best-studied rapidly oscillating Ap (roAp) stars, with eight known oscillation modes that are distorted by a strong, global magnetic field. We have reanalysed the multisite observations of HR 1217 taken in 1986 and…

太阳与恒星天体物理 · 物理学 2015-05-28 T. R. White , T. R. Bedding , D. Stello , D. W. Kurtz , M. S. Cunha , D. O. Gough

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…

天体物理学 · 物理学 2007-05-23 S. Hubrig , P. North , T. Szeifert

We present the discovery of a long-period, rapidly oscillating Ap star, HD177765. Using high-resolution time-series observations obtained with UVES at the ESO VLT telescope, we found radial velocity variations with amplitudes 7-150 m/s and…

太阳与恒星天体物理 · 物理学 2015-06-03 D. Alentiev , O. Kochukhov , T. Ryabchikova , M. Cunha , V. Tsymbal , W. Weiss

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…

太阳与恒星天体物理 · 物理学 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

We present the results of a survey using the WASP archive to search for high frequency pulsations in F-, A- and B-type stars. Over 1.5 million targets have been searched for pulsations with amplitudes greater than 0.5 millimagnitude. We…

We have investigated the structure of the pulsating atmosphere of one of the best studied rapidly oscillating Ap stars, HD 24712. For this purpose we analyzed spectra collected during 2001-2004. An extensive data set was obtained in 2004…

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…

太阳与恒星天体物理 · 物理学 2015-05-20 R. Arlt , G. Ruediger

Aims. Despite photometry and spectroscopy of its oscillations obtained over the past 25 years, the pulsation frequency spectrum of the rapidly oscillating Ap (roAp) star gamma Equ has remained poorly understood. Better time-series…

Stars with radiative envelopes, specifically the upper main sequence chemically peculiar (Ap) stars, were among the first objects outside our solar system for which surface magnetic fields have been detected. Currently magnetic Ap stars…

太阳与恒星天体物理 · 物理学 2015-06-17 O. Kochukhov

The many peculiarities of Ap stars (not only chemical ones, but also magnetic field and slow rotation) may vary during the main-sequence evolution of these stars. We review here briefly the evidences found in the last thirty years for such…

天体物理学 · 物理学 2009-06-25 P. North , J. Babel , D. Erspamer

Various observational properties of Ap/Bp stars have been well-established such as the often-cited 10% incidence rate of strong, organized magnetic fields amongst all A- and B-type stars. However, these inferences have generally been drawn…

太阳与恒星天体物理 · 物理学 2017-12-11 James Sikora , Gregg A. Wade , Jennifer Power

Observations of Epsilon UMa obtained with the star tracker on the Wide Field Infrared Explorer (WIRE) satellite during a month in mid-2000 are analyzed. This is one of the most precise photometry of an Ap star. The amplitude spectrum is…

天体物理学 · 物理学 2009-11-10 Alon Retter , Timothy R. Bedding , Derek L. Buzasi , Hans Kjeldsen , Laszlo L. Kiss

In this paper we describe and evaluate new spectral line polarisation observations obtained with the goal of mapping the surfaces of magnetic Ap stars in great detail. One hundred complete or partial Stokes IQUV sequences, corresponding to…

太阳与恒星天体物理 · 物理学 2015-06-05 J. Silvester , G. A. Wade , O. Kochukhov , S. Bagnulo , C. P. Folsom , D. Hanes

Highly magnetized neutron stars are promising candidates to explain some of the most peculiar astronomical phenomena, for instance, fast radio bursts, gamma-ray bursts, and superluminous supernovae. Pulsations of these highly magnetized…

高能天体物理现象 · 物理学 2023-03-13 Man Yin Leung , Anson Ka Long Yip , Patrick Chi-Kit Cheong , Tjonnie Guang Feng Li

This paper describes a study to deduce fundamental parameters and magnetic field characteristics for all magnetic Ap/Bp stars with in a 100 parsec heliocentric radius volume. This study has allowed for the first time the determination of an…

天体物理学 · 物理学 2007-05-23 J. Power , G. A. Wade , D. A. Hanes , M. Auriere , J. Silvester

Magnetic perturbations to the frequencies of low degree, high radial order, axisymmetric pulsations in stellar models permeated by large scale magnetic fields are presented. Magnetic fields with dipolar, quadrupolar and a superposition of…

天体物理学 · 物理学 2008-11-26 M. S. Cunha