English
Related papers

Related papers: Two New roAp Stars Discovered with TESS

200 papers

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…

Astrophysics · Physics 2009-11-10 S. Hubrig , D. W. Kurtz , S. Bagnulo , T. Szeifert , M. Schoeller , G. Mathys , W. A. Dziembowski

The Nainital-Cape Survey was initiated more than two decades ago aiming to search for and study the pulsational variability in two subclasses of chemically peculiar (CP) stars, namely the Ap and Am stars. In this paper, we present the TESS…

Solar and Stellar Astrophysics · Physics 2023-09-29 Athul Dileep , Santosh Joshi , Donald Wayen Kurtz

We report on an analysis of high-precision, multi-colour photometric observations of the rapidly-oscillating Ap (roAp) star $\alpha$ Cir. These observations were obtained with the BRITE-Constellation, which is a coordinated mission of five…

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

We report on the detection of pulsations of three pulsating subdwarf B stars observed by the TESS satellite and our results of mode identification in these stars based on an asymptotic period relation. SB 459 (TIC 067584818), SB 815 (TIC…

We present the first detailed photometric characterization of TIC 470127886, a previously unstudied multi-periodic variable star discovered in TESS photometry. Analysis of 145,374 high-cadence observations spanning 696 days (944-day…

Solar and Stellar Astrophysics · Physics 2025-12-12 Roo Weerasinghe

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 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

The RApid Temporal Survey (RATS) is a survey to detect objects whose optical intensity varies on timescales of less than ~70 min. In our pilot dataset taken with the INT and the Wide Field Camera in Nov 2003 we discovered nearly 50 new…

Astrophysics · Physics 2009-11-11 Gavin Ramsay , Ralf Napiwotzki , Pasi Hakala , Harry Lehto

Heartbeat stars are eccentric binaries exhibiting characteristic shape of brightness changes during periastron passage caused by tidal distortion of the components. Variable tidal potential can drive tidally excited oscillations (TEOs),…

The Transiting Exoplanet Survey Satellite (TESS) has enabled the discovery of numerous tidally tilted pulsators (TTPs), which are pulsating stars in close binaries where the presence of a tidal bulge has the effect of tilting the primary…

Light curves of 57 classical Be stars in TESS sectors 1 - 15 are examined. In most Be stars, the periodogram shows groups at a fundamental and one or more harmonics, which we attribute to rotation. In about 40 percent of the stars, the…

Solar and Stellar Astrophysics · Physics 2020-02-19 Luis A. Balona , Dogus Ozuyar

The discovery of a significant number of rapidly rotating low mass stars showing no or few flares in TESS observations was a surprise as rapid rotation has previously been taken as implying high stellar activity. Here we present TESS and…

Solar and Stellar Astrophysics · Physics 2025-11-12 Gavin Ramsay , J. G. Doyle , Stuart Littlefair , Vik Dhillon , David Alvarez Garcia

Precise time-series photometry with the MOST satellite has led to identification of 10 pulsation frequencies in the rapidly oscillating Ap (roAp) star HD 134214. We have fitted the observed frequencies with theoretical frequencies of…

Solar and Stellar Astrophysics · Physics 2015-05-30 H. Saio , M. Gruberbauer , W. W. Weiss , J. M. Matthews , T. Ryabchikova

In this paper, we present the observations of two new GW Vir stars from the extended \textit{TESS} mission in both 120\,s short-cadence and 20\,s ultra-short-cadence mode of two pre-white dwarf stars showing hydrogen deficiency. We…

We present an analysis of oscillation mode variability in the hot B subdwarf star EPIC~220422705, a new pulsator discovered from $\sim78$~days of {\em K}2 photometry. The high-quality light curves provide a detection of 66 significant…

Solar and Stellar Astrophysics · Physics 2022-07-27 Xiao-Yu Ma , Weikai Zong , Jian-Ning Fu , M. D. Reed , Jiaxin Wang , Stephane Charpinet , Jie Su

TESS is revolutionising the search for planets orbiting bright and nearby stars. In sectors 3 and 4, TESS observed TOI-402 (TIC-120896927), a bright V=9.1 K1 dwarf also known as HD 15337, and found two transiting signals with period of 4.76…

We report a multisite photometric campaign for the Beta Cep stars V2052 Oph and V986 Oph. 670 hours of high-quality differential photoelectric Stromgren, Johnson and Geneva time-series photometry were obtained with eight telescopes on five…

Chemically peculiar A stars (Ap) are extreme examples of the interaction of atomic element diffusion processes with magnetic fields in stellar atmospheres. The rapidly oscillating Ap stars provide a means for studying these processes in 3D…

Astrophysics · Physics 2009-11-13 L. M. Freyhammer , V. G. Elkin , D. W. Kurtz , G. Mathys , P. Martinez