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Related papers: Pulsation models for the roAp star HD 134214

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We discuss pulsations of the rapidly oscillating Ap (roAp) star HD 24712 (HR 1217) based on nonadiabatic analyses taking into account the effect of dipole magnetic fields. We have found that all the pulsation modes appropriate for HD 24712…

Solar and Stellar Astrophysics · Physics 2015-05-14 Hideyuki Saio , Tanya Ryabchikova , Mikhail Sachkov

We present 10.27$ \rm{hrs}$ of photometry of the roAp star HD 134214 obtained by the MOST satellite. The star is shown to be monoperiodic and oscillating at a frequency of 2948.97$ \pm 0.55 \mu\rm{Hz}$. This is consistent with earlier…

We report the frequency analysis of a known roAp star, HD 86181 (TIC 469246567), with new inferences from TESS data. We derive the rotation frequency to be $\nu_{rot}$ = 0.48753 $\pm$ 0.00001d$^{-1}$. The pulsation frequency spectrum is…

Solar and Stellar Astrophysics · Physics 2021-08-04 Fangfei Shi , Donald W. Kurtz , Daniel L. Holdsworth , Hideyuki Saio , Margarida S. Cunha , Huawei Zhang , Jianning Fu , G. Handler

We report on the analysis of high-precision space-based photometry of the roAp (rapidly oscillating Ap) stars HD 9289, HD 99563, and HD134214. All three stars were observed by the MOST satellite for more than 25 days, allowing unprecedented…

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…

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

Context: We present 31.2 days of nearly continuous MOST photometry of the roAp star 10Aql. Aims:The goal was to provide an unambiguous frequency identification for this little studied star, as well as to discuss the detected frequencies in…

We have obtained a time series of 81 high-cadence circular polarization observations of the rapidly oscillating Ap star HD 24712 with the new ESPaDOnS spectropolarimeter at CFHT. We used the high-S/N, high-resolution Stokes I and V spectra…

Astrophysics · Physics 2009-11-13 O. Kochukhov , G. A. Wade

Rapidly oscillating Ap stars are unique objects in the potential they offer to study the interplay between a number of important physical phenomena, in particular, pulsations, magnetic fields, diffusion, and convection. Nevertheless, the…

Solar and Stellar Astrophysics · Physics 2015-06-17 M. S. Cunha , D. Alentiev , I. M. Brandão , K. Perraut

We have carried out a survey of short-period pulsations among a sample of carefully chosen cool Ap stars using time-resolved observations with the UVES spectrometer at the ESO 8-m VLT telescope. Here we report the discovery of pulsations…

Solar and Stellar Astrophysics · Physics 2015-06-15 O. Kochukhov , D. Alentiev , T. Ryabchikova , S. Boyko , M. Cunha , V. Tsymbal , W. Weiss

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…

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…

Solar and Stellar Astrophysics · Physics 2015-05-28 T. R. White , T. R. Bedding , D. Stello , D. W. Kurtz , M. S. Cunha , D. O. Gough

We present the results of a multisite photometric observing campaign on the rapidly oscillating Ap (roAp) star 2MASS 16400299-0737293 (J1640; $V=12.7$). We analyse photometric $B$ data to show the star pulsates at a frequency of $151.93$…

We present our discovery of pulsational radial-velocity variations in the cool Ap star HD 75445, an object spectroscopically similar to the bright, rapidly-oscillating Ap (roAp) star gamma Equ. Based on high-resolution time-series…

Astrophysics · Physics 2009-11-13 O. Kochukhov , S. Bagnulo , G. Lo Curto , T. Ryabchikova

We have used high-speed spectroscopy of the rapidly oscillating Ap (roAp) star HD99563 to study the pulsation amplitude and phase behaviour of elements in its stratified atmosphere over one 2.91-d rotation cycle. We identify spectral…

Solar and Stellar Astrophysics · Physics 2015-05-13 L. M. Freyhammer , D. W. Kurtz , V. G. Elkin , G. Mathys , I. Savanov , W. Zima , H. Shibahashi , K. Sekiguchi

Context. The dipole modes are the most common geometry of oscillations in roAp stars inferred from photometric measurements and are therefore of special interest for asteroseismic purposes. Aims. We present a theoretical and analytical…

Solar and Stellar Astrophysics · Physics 2011-10-06 L. Bigot , D. W. Kurtz

We have discovered a new rapidly oscillating Ap star among the Kepler Mission target stars, KIC 10195926. This star shows two pulsation modes with periods that are amongst the longest known for roAp stars at 17.1 min and 18.1 min,…

We present a multi-instrument analysis of the rapidly oscillating Ap (roAp) star HD 42659. We have obtained $B$ photometric data for this star and use these data, in conjunction with TESS observations, to analyse the high-frequency…

Solar and Stellar Astrophysics · Physics 2019-09-25 Daniel L. Holdsworth , Hideyuki Saio , Donald W. Kurtz

We analyze the frequencies of three known roAp stars, TIC 96315731, TIC 72392575, and TIC 318007796, using the light curves from the Transiting Exoplanet Survey Satellite (TESS). For TIC 96315731, the rotational and pulsational frequencies…

Solar and Stellar Astrophysics · Physics 2024-07-24 Hai-Jian Zhong , Dong-Xiang Shen , Chun-Hua Zhu , He-Lei Liu , Su-Fen Guo , Guo-Liang Lü

We report the detection of short period variations in the stars HD69013 and HD96237. These stars possess large overabundances of rare earth elements and global magnetic fields, thus belong to the class of chemically peculiar Ap stars of the…

Solar and Stellar Astrophysics · Physics 2015-05-20 V. G. Elkin , D. W. Kurtz , H. L. Worters , G. Mathys , B. Smalley , F. van Wyk , A. M. S. Smith
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