We present the first results from the Transiting Exoplanet Survey Satellite (TESS) on the rotational and pulsational variability of magnetic chemically peculiar A-type stars. We analyse TESS 2-min cadence data from sectors 1 and 2 on a sample of 83 stars. Five new rapidly oscillating Ap (roAp) stars are announced. One of these pulsates with periods around 4.7 min, making it the shortest period roAp star known to date. Four out of the five new roAp stars are multiperiodic. Three of these, and the singly-periodic one show the presence of rotational mode splitting. Individual frequencies are provided in all cases. In addition, seven previously known roAp stars are analysed. Additional modes of oscillation are found in some stars, while in others we are able to distinguish the true pulsations from possible aliases present in the ground-based data. We find that the pulsation amplitude in the TESS filter is typically a factor 6 smaller than that in the B filter which is usually used for ground-based observations. For four roAp stars we set constraints on the inclination angle and magnetic obliquity, through the application of the oblique pulsator model. We also confirm the absence of roAp-type pulsations down to amplitude limits of 6 and 13 µmag, respectively, in two of the best characterised non-oscillating Ap (noAp) stars. We announce 27 new rotational variables along with their rotation periods, and provide different rotation periods for seven other stars. Finally, we discuss how these results challenge state-of-the-art pulsation models for roAp stars.

We present the first asteroseismic results for δ Scuti and γ Doradus stars observed in Sectors 1 and 2 of the TESS mission. We utilize the 2-min cadence TESS data for a sample of 117 stars to classify their behaviour regarding variability and place them in the Hertzsprung–Russell diagram using Gaia DR2 data. Included within our sample are the eponymous members of two pulsator classes, γ Doradus and SX Phoenicis. Our sample of pulsating intermediate-mass stars observed by TESS also allows us to confront theoretical models of pulsation driving in the classical instability strip for the first time and show that mixing processes in the outer envelope play an important role. We derive an empirical estimate of 74 per cent for the relative amplitude suppression factor as a result of the redder TESS passband compared to the Kepler mission using a pulsating eclipsing binary system. Furthermore, our sample contains many high-frequency pulsators, allowing us to probe the frequency variability of hot young δ Scuti stars, which were lacking in the Kepler mission data set, and identify promising targets for future asteroseismic modelling. The TESS data also allow us to refine the stellar parameters of SX Phoenicis, which is believed to be a blue straggler.

Aims. We study the fast rotating M 5 giant EK Boo by means of spectropolarimetry to obtain direct and simultaneous measurements of both the magnetic field and activity indicators, in order to infer the origin of the activity in this fairly evolved giant. Methods. We used the new spectropolarimeter NARVAL at the Bernard Lyot Telescope (Observatoire du Pic du Midi, France) to obtain a series of Stokes I and Stokes V profiles for EK Boo. Using the least square deconvolution (LSD) technique we were able to detect the Zeeman signature of the magnetic field. We measured its longitudinal component by means of the averaged Stokes V and Stokes I profiles. The spectra also permitted us to monitor the Ca ii K&H chromospheric emission lines, which are well known as indicators of stellar magnetic activity. Results. From ten observations obtained between April 2008 and March 2009, we deduce that EK Boo has a magnetic field, which varied in the range of −0.1 to −8 G. On March 13, 2009, a complex structure of Stokes V was observed, which might indicate a dynamo. We also determined the initial mass and evolutionary stage of EK Boo, based on up-to-date stellar evolution tracks. The initial mass is in the range of 2.0−3.6 M , and EK Boo is either on the asymptotic giant branch (AGB), at the onset of the thermal pulse phase, or at the tip of the first (or red) giant branch (RGB). The fast rotation and activity of EK Boo might be explained by angular momentum dredge-up from the interior, or by the merging of a binary. In addition, we observed eight other M giants, which are known as X-ray emitters, or to be rotating fast for their class. For one of these, β And, presumably also an AGB star, we have a marginal detection of magnetic field, and a longitudinal component B l of about 1 G was measured. More observations like this will answer the question whether EK Boo is a special case, or whether magnetic activity is, rather, more common among M giants than expected.

We have measured the projected rotational velocities (v sin i) of the mass donors for 29 S‐type symbiotic stars (SSs) using high‐resolution spectroscopic observations and the cross‐correlation function (CCF) method. The results of the CCF have been controlled with synthetic spectra. The typical rotational velocity of the K and M giants in S‐type symbiotics appeared to be 4.5 < v sin i < 11.7 km s−1. In a subsample of 16 S‐type SSs (with known orbital periods and well‐measured v sin i), 15 have deviations from synchronization less than the 3σ level. This means that we did not find evidence for a statistically significant deviation from the synchronization for any of these 15 objects. The deviation from synchronization is statistically significant (at confidence level >99 per cent) only for the recurrent nova RS Oph. For 22 S‐type symbiotics we give clues as to what their orbital periods could be.

We present results of a multi-site photometric campaign on the high-amplitude δ Scuti star KIC 6382916 in the Kepler field. The star was observed over a 85-d interval at five different sites in North America and Europe during 2011. Kepler photometry and ground-based multicolour light curves of KIC 6382916 are used to investigate the pulsational content and to identify the principal modes. High-dispersion spectroscopy was also obtained in order to derive the stellar parameters and projected rotational velocity. From an analysis of the Kepler time series, three independent frequencies and a few hundred combination frequencies are found. The light curve is dominated by two modes with frequencies f 1 = 4.9107 and f 2 = 6.4314 d −1 . The third mode with f 3 = 8.0350 d −1 has a much lower amplitude. We attempt mode identification by examining the amplitude ratios and phase differences in different wavebands from multicolour photometry and comparing them to calculations for different spherical harmonic degree, l. We find that the theoretical models for f 1 and f 2 are in a best agreement with the observations and lead to value of l = 1 modes, but the mode identification of f 3 is uncertain due to its low amplitude. Non-adiabatic pulsation models show that frequencies below 6 d −1 are stable, which means that the low frequency of f 1 cannot be reproduced. This is further confirmation that current models predict a narrower pulsation frequency range than actually observed.