A5052606238- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Astrophysical Phenomena and Observations
- History and Developments in Astronomy
- Geophysics and Gravity Measurements
- Astronomical and nuclear sciences
- Solar and Space Plasma Dynamics
- Molecular Spectroscopy and Structure
- Statistical and numerical algorithms
- Calibration and Measurement Techniques
- Advanced Combinatorial Mathematics
- Atmospheric Ozone and Climate
- Veterinary Equine Medical Research
- Scientific Measurement and Uncertainty Evaluation
- Reservoir Engineering and Simulation Methods
- Hydrocarbon exploration and reservoir analysis
- Scientific Research and Discoveries
- Phase Equilibria and Thermodynamics
- Chemical Thermodynamics and Molecular Structure
Nicolaus Copernicus Astronomical Center
2008-2024
Polish Academy of Sciences
2016-2024
University of Concepción
2011-2020
Millennium Institute of Astrophysics
2015-2019
Universidad Nacional de Concepción
2014
University of Warsaw
2009-2013
University of Chile
2011
University of Hawaiʻi at Mānoa
2009
Carnegie Observatories
2009
Pontificia Universidad Católica de Chile
2009
We present a distance determination to the Small Magellanic Cloud (SMC) based on an analysis of four detached, long-period, late-type eclipsing binaries discovered by Optical Gravitational Lensing Experiment (OGLE) survey. The components show negligible intrinsic variability. A consistent set stellar parameters was derived with low statistical and systematic uncertainty. absolute dimensions stars are calculated precision better than 3%. surface brightness–infrared color relation used derive...
This paper reports on the spectroscopic investigation of 101 Cepheids in Carina region. These extend previous samples by about 35% number and increase amount Galactic disk coverage especially direction l ≈ 270°. The new do not add much information to radial gradient, but provide a substantial azimuthal coverage. We find no dependence abundance over an 80° angle from center annulus 1 kpc depth centered Sun. A simple linear fit Cepheid data yields gradient d[Fe/H]/dRG = −0.055 ± 0.003 dex...
A novel method of analysis double-lined eclipsing binaries containing a radially pulsating star is presented. The combined pulsating-eclipsing light curve built up from purely grid created using an existing modeling tool. For every pulsation phase the instantaneous radius and surface brightness are taken into account, being calculated disentangled radial velocity its out-of-eclipse pulsational ratio components, respectively. best model found Markov Chain Monte Carlo method. applied to binary...
The extragalactic distance scale builds on the Cepheid period-luminosity (PL) relation. In this paper, we want to carry out a strictly differential comparison of absolute PL relations obeyed by classical Cepheids in Milky Way (MW), LMC and SMC galaxies. Taking advantage substantial metallicity difference among populations these three galaxies, establish possible systematic trend relation zero point as function metallicity, determine size such an effect optical near-infrared photometric...
Using a sample of 81 galactic, detached eclipsing binary stars we investigated the global zero-point shift their parallaxes with Gaia Data Release 2 (DR2) parallaxes. The in lay distance range 0.04-2 kpc from Sun. photometric {\pi}_Phot binaries were determined by applying number empirical surface brightness - color (SBC) relations calibrated on optical-infrared colors. For each SBC relation calculated individual differences d{\pi}_i = ({\pi}_Gaia {\pi}_Phot)_i and then unweighted weighted...
Accurate masses and radii for normal stars derived from observations of detached eclipsing binary are fundamental importance testing stellar models may be useful calibrating free parameters in these model if the sufficiently precise accurate. We aim to measure bright AI Phe, quantify level systematic error estimates. use several different methods TESS light curve Phe combined with spectroscopic orbits multiple sources estimate precisely together robust find that agreement between analysis is...
We have analyzed the double-lined eclipsing binary system OGLE-051019.64-685812.3 in LMC which consists of two G4 giant components with very similar effective temperatures.A detailed analysis OGLE I-band light curve system, radial velocity curves for both derived from high-resolution spectra, and near-infrared magnitudes measured outside eclipses has allowed us to obtain an accurate orbit solution this binary, its fundamental physical parameters.Using a surface brightness-(V-K) color...
Motivated by an amazing range of reported distances to the nearby Local Group spiral galaxy M33, we have obtained deep near-infrared photometry for 26 long-period Cepheids in this with ESO Very Large Telescope. From data, constructed period–luminosity relations J and K bands which together previous optical VI Macri et al. were used determine true distance modulus mean reddening affecting Cepheid sample multiwavelength fit method developed Araucaria Project. We find a 24.62 total uncertainty...
We have analyzed the double-lined eclipsing binary system OGLE-LMC-CEP-1812 in LMC and demonstrate that it contains a classical fundamental mode Cepheid pulsating with period of 1.31 days. The secondary star is stable giant. derive dynamical masses for both stars an accuracy 1.5%, making this second very accurate mass determination, following OGLE-LMC-CEP-0227 studied by Pietrzyński et al. measured agrees well predicted pulsation models. also radii components orbital parameters system. This...
Based on new observations and improved modeling techniques, we have reanalyzed seven Cepheids in the Large Magellanic Cloud. Improved physical parameters been determined for exotic system OGLE LMC-CEP-1718 composed of two first-overtone a completely model was obtained LMC-CEP-1812 classical Cepheid. This is now shortest period Cepheid which projection factor measured. The typical accuracy our dynamical masses radii determinations 1%. six follow period--radius relations literature. Our very...
Abstract Cepheid stars play a considerable role as extragalactic distances indicators, thanks to the simple empirical relation between their pulsation period and luminosity. They overlap with that of secondary distance such Type Ia supernovae, whose scale is tied luminosities. However, period–luminosity (P–L) still lacks calibration better than 5%. Using an original combination interferometric astrometry optical ultraviolet spectroscopy, we measured geometrical <?CDATA $d=720.35\pm 7.84$?>...
We aim to measure very precise and accurate model-independent masses distances of detached binary stars. Precise at the $< 1$% level are necessary test calibrate stellar interior evolution models, while independent orbital parallaxes essential check for next Gaia data releases. combined RV measurements with interferometric observations determine physical parameters ten double-lined spectroscopic systems. report new relative astrometry from VLTI/GRAVITY and, some systems, VLT/UVES spectra...
We present a new Bayesian approach to constrain the intrinsic parameters (stellar mass, age) of eclipsing binary system CEP0227 in LMC. computed evolutionary models covering broad range chemical compositions and stellar mass. Independent sets were constructed either by neglecting or including moderate convective core overshooting (beta=0.2) during central H-burning phases. Models also assuming canonical (eta=0.4,0.8) an enhanced (eta=4) mass loss rate. The solutions three different planes:...
We present non-linear hydrodynamic pulsation models for OGLE-BLG-RRLYR-02792 - a 0.26M_sun pulsator, component of the eclipsing binary system, analysed recently by Pietrzynski et al. The star's light and radial velocity curves mimic that classical RR Lyrae stars, except bump in middle ascending branch curve. show is caused 2:1 resonance between fundamental mode second overtone same mechanism causes Hertzsprung progression Cepheids. allow to constrain parameters star, particular estimate its...
We present a detailed study of the classical Cepheid in double-lined, highly eccentric eclipsing binary system OGLE-LMC562.05.9009. The is fundamental mode pulsator with period 2.988 days. orbital 1550 Using spectroscopic data from three 4-8-m telescopes and photometry spanning 22 years, we were able to derive dynamical masses radii both stars exquisite accuracy. Both are very similar mass, radius color, but companion stable, non-pulsating star. slightly more massive bigger (M_1 = 3.70 +/-...
We performed a new and accurate fit of light radial velocity curves the Large Magellanic Cloud (LMC) Cepheid --OGLE-LMC-CEP-0227-- belonging to detached double-lined eclipsing binary system. computed several sets nonlinear, convective models covering broad range in stellar mass, effective temperature chemical composition. The comparison between theory observations indicates that current theoretical framework accounts for luminosity --V I band-- variations over entire pulsation cycle....
The aim of this work is to improve the SBC relation for early-type stars in $-1 \leq V-K 0$ color domain, using optical interferometry. Observations eight B- and A-type were secured with VEGA/CHARA instrument visible. derived uniform disk angular diameters converted into limb darkened included a larger sample 24 stars, already observed by interferometry, order derive revised empirical O, B, A spectral type index ranging from -1 0. We also took opportunity check consistency up $V-K \simeq 4$...
Abstract We present a determination of the precise fundamental physical parameters 20 detached, double-lined, eclipsing binary stars in Large Magellanic Cloud (LMC) containing G- or early K-type giant stars. Eleven are new systems; remaining nine systems already analyzed by our team for which we updated parameters. The catalog results from long-term survey binaries Clouds suitable high-precision distances (the Araucaria Project). V -band brightnesses range 15.4 to 17.7 mag, and their orbital...
Context. The projection factor p is the key quantity used in Baade-Wesselink (BW) method for distance determination; it converts radial velocities into pulsation velocities. Several methods are to determine , such as geometrical and hydrodynamical models or inverse BW approach when known. Aims. We analyze new HARPS-N spectra of δ Cep measure its cycle-averaged atmospheric velocity gradient order better constrain factor. Methods. first apply derive directly from observations. can be divided...
Abstract We present the results from a complex study of an eclipsing O-type binary (Aa+Ab) with orbital period P A = 3.2254367 days that forms part higher-order multiple system in configuration (A+B)+C. derived masses Aa+Ab M 1 19.02 ± 0.12 and 2 17.50 0.13 ⊙ , radii R 7.70 0.05 6.64 0.06 temperatures T 34,250 500 K 33,750 K. From analysis radial velocities, we found spectroscopic orbit outer A+B 195.8 ( / ≈ 61). In O − C analysis, confirmed this another component orbiting AB+C 2550 13)....