A5087731703- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Geophysics and Gravity Measurements
- Gamma-ray bursts and supernovae
- Atmospheric Ozone and Climate
- Mathematics and Applications
- Pulsars and Gravitational Waves Research
- Advanced Mathematical Theories and Applications
- Spectroscopy and Laser Applications
- Advanced Differential Equations and Dynamical Systems
- Adaptive optics and wavefront sensing
- Geological Studies and Exploration
- Scientific Research and Discoveries
- Atomic and Subatomic Physics Research
University of Wrocław
2019-2024
University of Liège
2024
Astronomical Institute of the Slovak Academy of Sciences
2021
We present the first results from Transiting Exoplanet Survey Satellite (TESS) on rotational and pulsational variability of magnetic chemically peculiar A-type stars. analyse TESS 2-min cadence data sectors 1 2 a sample 83 Five new rapidly oscillating Ap (roAp) stars are announced. One these pulsates with periods around 4.7 min, making it shortest period roAp star known to date. Four out five multiperiodic. Three singly periodic one show presence mode splitting. Individual frequencies...
Heartbeat stars are eccentric binaries exhibiting characteristic shape of brightness changes during periastron passage caused by tidal distortion the components. Variable potential can drive tidally excited oscillations (TEOs), which usually gravity modes. Studies heartbeat and TEOs open a new possibility to probe interiors massive stars. There only few (masses components $\gtrsim 2 $M$_\odot$) systems this type known. Using TESS data from first 16 sectors, we searched for using sample over...
We present the discovery and asteroseismic analysis of a new g-mode hot B subdwarf (sdB) pulsator, EC 21494-7018 (TIC 278659026), monitored in TESS first sector using 120-second cadence. The light curve reveals that is sdB pulsator counting up to 20 frequencies associated with independent g-modes. seismic singles out an optimal model solution full agreement measurements provided by spectroscopy (atmospheric parameters derived from atmospheres) astrometry (distance evaluated Gaia DR2...
Abstract We present time-series photometry of 21 nearby type II Cepheids in the near-infrared J , H and K s passbands. use this photometry, together with Third Gaia Early Data Release parallaxes, to determine for first time period–luminosity relations (PLRs) from field representatives these old pulsating stars regime. found PLRs be very narrow BL Herculis stars, which makes them candidates precision distance indicators. then archival most accurate obtained eclipsing binaries recalibrate...
Massive and intermediate-mass stars reside in binary systems much more frequently than low-mass stars. Binaries containing massive main-sequence (MS) component(s) are often characterised by eccentric orbits, can be observed as ellipsoidal variables (EEVs). The orbital phase-dependent tidal potential acting on the components of EEV induce tidally excited oscillations (TEOs). We investigate how history resonances between eigenmode spectra forcing frequencies depends initial parameters system....
Context. The evolution of massive stars is dominated by interactions within binary and multiple systems. In order to accurately model this evolution, it necessary investigate all possible forms an interaction in systems that may affect the components. One “laboratories” plausible for kind investigation eccentric system MACHO 80.7443.1718 (ExtEV), which exhibits exceptionally large amplitude light variability close periastron passage its 32.8-day orbit. Aims. We examine whether ExtEV can be...
We present an analysis of 991 heartbeat stars (HBSs) from the OGLE Collection Variable Stars (OCVS). The sample consists 512 objects located toward Galactic bulge (GB), 439 in Large Magellanic Cloud (LMC) and 40 Small (SMC). model $I$-band light curves using analytical flux variations, reflecting tidal deformations between stars. distributions parameters that include eccentricity, orbital inclination, argument periastron, but also period-amplitude diagrams. On Hertzsprung-Russell (HR)...
We present a collection of 991 heartbeat star (HBS) candidates found in the Optical Gravitational Lensing Experiment (OGLE) project data archive. discuss selection process HBS and structure catalog itself. It consists 512 stars located toward Galactic bulge (GB), 439 Large Magellanic Cloud (LMC), 40 Small (SMC). The contains two large groups HBSs with different physical properties. main distinction between is evolutionary status primary star. first group about 100 systems hot main-sequence...
Blue large-amplitude pulsators (BLAPs) form a small group of hot objects pulsating in fundamental radial mode with periods the order 30 minutes. Proposed evolutionary scenarios explain them as evolved low-mass stars: either ~0.3 M$_\odot$ shell-hydrogen-burning degenerated helium core, or more massive (0.5 - 0.8) core-helium-burning stars, ~0.7 surviving companions type Ia supernovae. Therefore, their origin remains to be established. Using data from Transiting Exoplanet Survey Satellite, we...
We present a complex study of the eclipsing binary system, AB Cas. The analysis whole TESS light curve, corrected for effects, reveals 112 significant frequency peaks with 17 independent signals. dominant $f_1 = $17.1564 d$^{-1}$ is radial fundamental mode. $O-C$ times minima from over 92 years leads to conclusion that due ongoing mass transfer system exhibits change orbital period at rate 0.03 s per year. In order find evolutionary models describing current stage Cas, we perform evolution...
Context. Eccentric ellipsoidal variables (also known as heartbeat stars) is a class of eccentric binaries in which proximity effects, and tidal distortion due to time-dependent potential particular, lead measurable photometric variability close the periastron passage. Varying may also give rise tidally excited oscillations (TEOs), are forced eigenmodes with frequencies integer multiples orbital frequency. TEOs play an important role dynamical evolution massive systems. Aims. Our study aimed...
Context. Blue large-amplitude pulsators (BLAPs) are a recently discovered group of hot stars pulsating in radial modes. Their origin needs to be explained, and several scenarios for their formation have already been proposed. Aims. We investigate whether BLAPs can originate as the product merger two low-mass white dwarfs (WDs) estimate how many formed this evolutionary channel. Methods. used Modules Experiments Stellar Astrophysics (MESA) code model three different double extremely (DELM)...
Blue large-amplitude pulsators (BLAPs) are a newly discovered group of compact pulsating stars whose origins yet to be explained. Of the existing evolutionary scenarios that could lead formation BLAPs, there two positing BLAPs products merger stars: either main-sequence star and helium white dwarf or low-mass dwarfs. Among over hundred known three equidistant modes, in terms frequency, had been found one, namely, OGLE-BLAP-001. We show modes similarly frequency do exist another BLAP,...
$\delta$ Orionis is the closest massive multiple stellar system and one of brightest members Orion OB association. The primary (Aa1) a unique evolved O star. In this work, we applied two-step disentangling method to series spectra in blue region (430 450 nm), detected spectral lines secondary (Aa2). For first time, were able constrain orbit tertiary (Ab) - 55 d or 152 yr using variable $\gamma$ velocities new speckle interferometric measurements, which have been published Washington Double...
Blue large-amplitude pulsators (BLAPs) are a recently discovered group of hot stars pulsating in radial modes. Their origin needs to be explained, and several scenarios for their formation have already been proposed. We investigate whether BLAPs can originate as the product merger two low-mass white dwarfs (WDs) estimate how many formed this evolutionary channel. used MESA code model three different double extremely (DELM) WDs subsequent evolution product. also performed population synthesis...
Blue large-amplitude pulsators (BLAPs) are a newly discovered group of compact pulsating stars whose origin needs to be explained. Of the existing evolutionary scenarios that could lead formation BLAPs, there two in which BLAPs products merger stars, either main sequence star and helium white dwarf or low-mass dwarfs. Among over hundred known three equidistant frequency modes had been found one, OGLE-BLAP-001. We show similar exist yet another BLAP, ZGP-BLAP-08. This perfect separation is...
The evolution of massive stars is heavily influenced by their binarity, and the eccentric binary system MACHO 80.7443.1718 (ExtEV) serves as a prime example. This study explores whether light variability ExtEV, observed near periastron during its 32.8-day orbit, can be explained wind-wind collision (WWC) model reviews other potential explanations. Using broadband photometry, TESS data, ground-based $UBV$ time-series high-resolution spectroscopy, we analysed system's parameters. We ruled out...
The evolution of massive stars is heavily influenced by their binarity, and the eccentric binary system MACHO 80.7443.1718 (ExtEV) serves as a prime example. This study explores whether light variability ExtEV, observed near periastron during its 32.8-day orbit, can be explained wind–wind collision (WWC) model reviews other potential explanations. Using broadband photometry, TESS data, ground-based UBV time-series high- resolution spectroscopy, we analysed system’s parameters. We ruled out...
Abstract HD 66051 is an eclipsing and spectroscopic double-lined binary (SB2), hosting two chemically peculiar stars: a highly B star as primary Am secondary. The investigation of the new high-resolution UVES spectrum allowed us to decide on chemical peculiarity type both components with more reliability. An analysis TESS photometric time series data will further specify physical parameters stars orbital system.
Massive and intermediate-mass stars reside in binary systems much more frequently than low-mass stars. Binaries containing massive main-sequence (MS) component(s) are often characterised by eccentric orbits, can be observed as ellipsoidal variables (EEVs). The orbital phase-dependent tidal potential acting on the components of EEV induce tidally excited oscillations (TEOs). We investigate how history resonances between eigenmode spectra forcing frequencies depends initial parameters system....
Evolution of massive stars is dominated by interactions within binary systems. Therefore, it necessary to investigate all forms interaction in systems that may affect the evolution components. One such laboratories eccentric system MACHO$\,$80.7443.1718 (ExtEV). We examine whether light variability ExtEV can be explained a wind-wind collision (WWC) model. conducted an analysis broadband multi-color photometry ExtEV, time-series space from TESS, ground-based Johnson $UBV$ photometry, and...
HD 66051 (V414 Pup) is an eclipsing and spectroscopic double-lined binary, hosting two chemically peculiar stars: a highly B star as primary Am secondary.It also shows out-of-eclipse variability that due to chemical spots.Using set of high-resolution spectropolarimetric observations, weak magnetic field on the was found.The investigation new UVES spectrum allowed us decide peculiarity type both components with more reliability.