Related papers: The roAp star $\alpha$ Circini as seen by BRITE-Co…

Highly precise and nearly uninterrupted optical photometry of the RR Lyrae star AQ Leo was obtained with the MOST (Microvariability & Oscillations of STars) satellite over 34.4 days in February-March 2005. AQ Leo was the first known…

We present observations of the neutron star X-ray binary and relativistic jet source Circinus X-1 made at 4.8 and 8.6 GHz with the Australia Telescope Compact Array during a time interval of almost 10 years. The system shows significant…

We have analysed the photometric data obtained with the STEREO spacecraft for 558 non-magnetic chemically peculiar (CP) stars to search for rotational and pulsational variability. Applying the Lomb-Scargle and the phase dispersion…

We studied the variability of the magnetic O-type supergiant $\zeta$ Ori Aa using multi-colour BRITE photometry. We confirmed the known rotation frequency $f_{\rm rot} = 0.15 \pm 0.02$ c/d, and detected some of its higher harmonics, of…

Before the launch of the Kepler Space Telescope, most studies of the rapidly oscillating Ap (roAp) stars were conducted with ground-based photometric $B$ observations, supplemented with high-resolution time-resolved spectroscopy and some…

We report the results of a 60-hr photometric campaign of a rapidly oscillating Ap star, J0855 (TYC 2488-1241-1). We have utilised the multi-site Las Cumbres Observatory's (LCO) 0.4-m telescopes to obtain short cadence B-band observations of…

We present new optical spectroscopy and photometry, 2MASS infrared observations and 24 years of combined AAVSO and AFOEV photometry of the symbiotic star candidate \ae. The long-term light curve is characterized by outbursts lasting several…

The star CoRoT102781750 reveals a puzzle, showing a very complex and altering variation in different `CoRoT colours'. We established without doubt that more than a single star was situated within the CoRoT mask. Using a search for…

The radio spectra of main-sequence stars remain largely unconstrained due to the lack of observational data to inform stellar atmosphere models. As such, the dominant emission mechanisms at long wavelengths, how they vary with spectral…

The spectrophotometric variability of the magnetic CP star 56 Arietis (56 Ari) in the ultraviolet spectral region from 1950 to 3200 A is investigated. This study is based on the archival International Ultraviolet Explorer data obtained at…

The 76 frequencies determined from Kepler measurements of the A-type star KIC 9700322 can be understood in a rather simple way as the radial fundamental and first overtone radial modes, a nonradial \ell = 2 quintuplet, stellar rotation and…

We present the analysis of 65 hours of high speed photometric observations of HD 12098 taken from State Observatory, Naini Tal and Gurushikhar Observatory, Mt.Abu on sixteen nights spanning from November 1999 to November 2000. HD 12098 is…

Around 200 bright stars (V < 6) have been monitored with the two-inch star tracker on the WIRE satellite since observations started in 1999. Here we present new results for the solar-like star Procyon A, the two Delta Scuti stars Altair and…

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…

Although delta Scorpii is a bright and well-studied star, the details of its multiplicity have remained unclear. Here we present the first diffraction-limited image of this 0.12 arcsec binary star, made using optical interferometry, and…

We study the chromosphere and corona of the ultra-fast rotator AB Dor A at high temporal and spectral resolution using simultaneous observations with XMM-Newton in the X-rays, VLT/UVES in the optical, and the ATCA in the radio. Our optical…

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…

BS Cir is a representative of moderately cool magnetic chemically peculiar stars which displays very strong light variations in Stroemgren index c1 indicating large changes in the height of the Balmer jump. We present two-spot model of…

The rotation periods of Ap stars span more than five orders of magnitude. The physical origin of this differentiation remains poorly understood. The consideration of the most slowly rotating Ap stars represents a promising approach to gain…

Context. OB stars are important building blocks of the Universe, but we have only a limited sample of them well understood enough from an asteroseismological point of view to provide feedback on the current evolutionary models. Our study…