相关论文: Super-slowly rotating Ap (ssrAp) stars: Spectrosco…

Current knowledge about stellar magnetic fields relies almost entirely on circular polarization observations. Few objects have been observed in all four Stokes parameters. The magnetic Ap star HD 24712 (DO Eri, HR 1217) was recently…

The positions in the H-R diagram of strongly magnetic Ap and Bp stars are compared with those of normal main sequence stars of types B7 to F2, with a view to investigating possible differences in evolutionary status between magnetic and…

Context. A thousand new magnetic candidate CP stars have been identified with LAMOST, among which about 700 prime targets have rotational modulation determined from TESS. Aims. We aim to check for the presence of a magnetic field in a…

Many stars, including those in binary or multiple systems, exhibit modified rotational evolution due to tidal interactions. While magnetic braking slows rotation in single stars, close binaries experience synchronization from tidal forces,…

We report the results of our search for pulsating subdwarf B stars in Full Frame Images collected during Year 2 of the TESS mission and covering the northern ecliptic hemisphere. This is a continuation of our effort we presented in Paper I.…

We present an analysis of a volume-complete sample of 363 mid-to-late M dwarfs within 15 pc of the Sun with masses between 0.1 and 0.3 M$_\odot$ observed by TESS within Observation Sectors 1 to 42. The median mass of the stars in this…

The extraordinary magnetic Ap star HD75049 has been studied with data obtained with the ESO VLT and 2.2-m telescopes. Direct measurements reveal that the magnetic field modulus at maximum reaches 30kG. The star shows photometric, spectral…

Observations made using TESS revealed a sample of low mass stars which show a periodic modulation on a period $<0.2$~d. Surprisingly many of these Ultra Fast Rotating (UFR) stars showed no evidence of flare activity which would be expected…

The new photometric data on pulsating Ap star HD~27463 obtained recently with the Transiting Exoplanet Survey Satellite (\textit{TESS}) are analysed to search for variability. Our analysis shows that HD~27463 exhibits two types of…

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…

Time-resolved spectroscopic observations of rapidly oscillating Ap (roAp) stars show a complex picture of propagating magneto-acoustic pulsation waves, with amplitude and phase strongly changing as a function of atmospheric height. We have…

We focus on early-B type stars with helium overabundance, for which the presence of a magnetic field has not previously been reported. The measurements were carried out using high-spectral-resolution spectropolarimetric observations…

It is well established that late-type main-sequence stars display a relationship between X-ray activity and the Rossby number, $Ro$, the ratio of rotation period to the convective turnover time. This manifests itself as a saturated regime…

We present the results of time-resolved photometry, abundance analysis and Doppler imaging of an Ap star, HD 100357. The {\it TESS} photometry revealed rotational modulation with a period of 1.6279247 days. Upon inspecting the residuals…

Stellar rotation is a fundamental tracer of stellar magnetic evolution, age, and activity, with broad implications for Galactic archaeology and exoplanet characterization. The Transiting Exoplanet Survey Satellite (TESS) provides…

Strong magnetic fields in chemically peculiar A-type (Ap) stars typically suppress low-overtone pressure modes (p modes) but allow high-overtone p modes to be driven. KIC 11296437 is the first star to show both. We obtained and analysed a…

We have obtained time-resolved spectroscopic observations for a sample of 10 cool Ap stars using the ultra-stable spectrograph HARPS at the ESO 3.6-m telescope. The aim of our study was to search for low-amplitude oscillations in Ap stars…

We use 1-m class telescopes and the Transiting Exoplanet Survey Satellite (TESS) to explore the photometric variability of all known rapidly rotating ($v\sin{i}\gtrsim30$ km\,s$^{-1}$) ultra-cool ($\geq$M7) dwarfs brighter than…

About 22000 Kepler stars and nearly 60000 TESS stars from sectors 1-24 have been classified according to variability type. A large proportion of stars of all spectral types appear to have periods consistent with the expected rotation…

Using \tess\ short-cadence (120\,s) SAP flux, we identified a rotational frequency of 0.09655\,$\mathrm{d}^{-1}$ ($P_\mathrm{rot}=10.35733$\,d). Wavelet analysis reveals that while the amplitudes of the harmonic components vary over time,…