A5012507960- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Galaxies: Formation, Evolution, Phenomena
- Solar and Space Plasma Dynamics
- Particle Accelerators and Free-Electron Lasers
- High-pressure geophysics and materials
- Neutrino Physics Research
- Gyrotron and Vacuum Electronics Research
- Geophysics and Gravity Measurements
- Adaptive optics and wavefront sensing
- History and Developments in Astronomy
- Cosmology and Gravitation Theories
- Calibration and Measurement Techniques
- Precipitation Measurement and Analysis
- Statistical and numerical algorithms
- Adhesion, Friction, and Surface Interactions
- Atmospheric Ozone and Climate
Jagiellonian University
2016-2025
Astronomical Observatory
2001-2025
Uniwersytet Komisji Edukacji Narodowej w Krakowie
2014-2023
Universidad Nacional Autónoma de México
2014
Pedagogical University
1996-2012
Cracow University of Technology
1998
Polish Academy of Sciences
1998
ABSTRACT OJ 287 is a quasi-periodic quasar with roughly 12 year optical cycles. It displays prominent outbursts that are predictable in binary black hole model. The model predicted major outburst 2015 December. We found the did occur within expected time range, peaking on December 5 at magnitude 12.9 R -band. Based Swift /XRT satellite measurements and polarization data, we find it included thermal component. Its timing provides an accurate estimate for spin of primary hole, . present also...
Detection of periodicity in the broad-band non-thermal emission blazars has so far been proven to be elusive. However, there are a number scenarios which could lead quasi-periodic variations blazar light curves. For example, orbital or thermal/viscous period accreting matter around central supermassive black holes could, principle, imprinted multi-wavelength small-scale jets, carrying as such crucial information about plasma conditions within jet launching regions. In this paper, we present...
Abstract We present the results of our power spectral density analysis for BL Lac object OJ 287, utilizing Fermi -LAT survey at high-energy γ -rays, Swift -XRT in X-rays, several ground-based telescopes and Kepler satellite optical, radio GHz frequencies. The light curves are modeled terms continuous-time autoregressive moving average (CARMA) processes. Owing to inclusion data, we were able construct first time optical variability spectrum a blazar without any gaps across ∼6 dex temporal Our...
Binary black hole (BH) central engine description for the unique blazar OJ 287 predicted that next secondary BH impact-induced bremsstrahlung flare should peak on 2019 July 31. This prediction was based detailed general relativistic modeling of trajectory around primary and its accretion disk. The expected termed Eddington to commemorate centennial celebrations now-famous solar eclipse observations test relativity by Sir Arthur Eddington. We analyze multi-epoch Spitzer between 31 September...
Abstract Gamma-ray bursts (GRBs) are fascinating events due to their panchromatic nature. We study optical plateaus in GRB afterglows via an extended search into archival data. comprehensively analyze all published GRBs with known redshifts and observed by many ground-based telescopes (e.g., Subaru Telescope, RATIR) around the world several space-based observatories such as Neil Gehrels Swift Observatory. fit 500 light curves, showing existence of plateau 179 cases. This sample is 75% larger...
Abstract We report the study of a huge optical intraday flare on 2021 November 12 at 2 a.m. UT in blazar OJ 287. In binary black hole model, it is associated with an impact secondary accretion disk primary. Our multifrequency observing campaign was set up to search for such signature based prediction made 8 yr earlier. The first I -band results have already been reported by Kishore et al. (2024). Here we combine these data our monitoring R -band. There big change – spectral index 1.0 ± 0.1...
ABSTRACT We present the largest optical photometry compilation of gamma-ray bursts (GRBs) with redshifts (z). include 64813 observations 535 events (including upper limits) from 28 February 1997 to 18 August 2023. also a user-friendly web tool grbLC which allows users visualize photometry, coordinates, redshift, host galaxy extinction, and spectral indices for each event in our database. Furthermore, we have added Gamma-ray Coordinate Network (GCN) scraper that can be used collect data by...
We present results of the modelling multicolour light curves 10 contact binary systems: V376 And, V523 Cas, CC Com, BX Dra, FG Hya, UZ Leo, XY AM EX Leo and RT LMi. The solutions resulted in a configuration for all systems. found only Hya to be deep contact, latter almost filling outer critical lobe. absolute parameters components have been determined with an accuracy about few per cent based on combined photometric radial velocity curves, enlarging sample systems 58 which physical obtained...
The bright blazar OJ~287 routinely parades high brightness bremsstrahlung flares, which are explained as being a result of secondary supermassive black hole (SMBH) impacting the accretion disc more massive primary SMBH in binary system. is not rigid but rather bends calculable way due to tidal influence secondary. Below we refer this phenomenon variable level. We begin by showing that these flares occur at times predicted simple analytical formula, based on general relativity inspired...
We report the discovery of an eclipsing binary -HS 0705+6700 -being sdB star with a faint companion. From its light curve orbital period 8263.87 s, mass ratio system , inclination 84 and other parameters are derived. The companion does not contribute to optical except through strong reflection effect. semi-amplitude radial velocity km s-1 function determined. A spectroscopic analysis blue spectra results in K, . These characteristics typical for stars, as is 0.48 According (0.13 ) radius...
HS 0705+6700 is a short-period (P = 2.3 hr), close binary containing hot sdB-type primary and fully convective secondary. We have monitored this eclipsing for more than two years as result, 32 times of light minimum were obtained. Based on our new eclipse together with these compiled from the literature, it discovered that observed–calculated curve shows cyclic variation period 7.15 semiamplitude 92.4 s. The periodic change was analyzed light-travel time effect may be due to presence...
We have studied three most recent precursor flares in the light curve of blazar OJ 287 while invoking presence a precessing binary black hole system to explain nature these flares. Precursor flare timings from historical curves are compared with theoretical predictions our model that incorporate effects an accretion disk and post-Newtonian description for orbit. find coincide secondary descending towards primary observed side, mean z-component approximately z_c = 4000 AU. use this predict...
The cyclic behaviour of (O-C) residuals eclipse timings in the sdB+M eclipsing binary NSVS 14256825 was previously attributed to one or two Jovian-type circumbinary planets. We report 83 new that not only fill gaps those already published but also extend time span diagram by three years. Based on archival and our data spanning over more than 17 years we re-examined up date system (O-C). revealed systematic, quasi-sinusoidal variation deviating from an older linear ephemeris about 100 s. It...
The bright blazar OJ 287 is the best-known candidate for hosting a nanohertz gravitational wave (GW) emitting supermassive binary black hole (SMBBH) in present observable universe. (BBH) central engine model, proposed by Lehto and Valtonen 1996, was influenced two distinct periodicities inferred from optical light curve of 287. current improved model employs an accurate general relativistic description to track trajectory secondary (BH) which crucial predict inherent impact flares successful...
Binary and multiple stellar systems are numerous in our solar neighborhood with 80 per cent of the solar-type stars being members high order multiplicity. The Contact Binaries Towards Merging (CoBiToM) Project is a programme that focuses on contact binaries systems, as key for understanding nature. goal to investigate coalescence merging processes, final state evolution low-mass binary systems. Obtaining observational data approximately 100 eclipsing more than 400 archival aspires give...
We present the results of variability power spectral density (PSD) analysis using multiwavelength radio to GeV\,$\gamma$-ray light curves covering decades/years days/minutes timescales for blazars 3C 279 and PKS 1510-089. The PSDs are modeled as single power-laws, best-fit shape is derived `power response' method. With more than ten years data obtained with weekly/daily sampling intervals, most cover ~2-4 decades in temporal frequency; moreover, optical band, ~6 due availability intranight...
92 h of new Whole Earth Telescope observations have been acquired for the δ Scuti star CD-24 7599. All seven pulsation modes reported by Handler et al. are confirmed. However, significant amplitude variations which not caused beating closely spaced frequencies occurred within two years. Analysing combined data both WET runs, we detect six further modes, bringing total number up to 13. We also examine our high-frequency pulsations similar those exhibited rapidly oscillating Ap stars, but do...
HR 1217 is one of the best-studied rapidly oscillating Ap (roAp) stars, with a frequency spectrum alternating even- and odd-ℓ modes that are distorted by presence strong, global magnetic field. Several recent theoretical studies have found within observable atmospheres roAp stars pulsation magneto-acoustic significant perturbations cyclic increasing frequency. To test these theories Whole Earth Telescope extended coverage campaign obtained 342 h Johnson B data at 10-s time resolution for...
BPM 37093 is the only hydrogen-atmosphere white dwarf currently known which has sufficient mass (~ 1.1 M_sun) to theoretically crystallize while still inside ZZ Ceti instability strip (T_eff ~ 12,000 K). As a consequence, this star represents our first opportunity test crystallization theory directly. If core substantially crystallized, then inner boundary for each pulsation mode will be located at top of solid rather than center star, affecting mainly average period spacing. This distinct...
The blazar OJ 287 has produced two major optical outburst events during the years 2005–2008. These are latest in a series of outbursts that have occurred repeatedly at 12 year intervals since early 1900s. It been possible to explain historical light curve fairly well by using binary black hole model where secondary impacts accretion disk primary twice orbital cycle. We will ask here how does light-curve fit with this model. use 10 million particle hole. rate transfer particles through...
We report on analysis of 308.3 hrs high speed photometry targeting the pulsating DA white dwarf EC14012-1446. The data were acquired with Whole Earth Telescope (WET) during 2008 international observing run XCOV26. Fourier transform light curve contains 19 independent frequencies and numerous combination frequencies. dominant peaks are 1633.907, 1887.404, 2504.897 microHz. Our amplitudes reveals that parent consistent modes spherical degree l=1. also provide m identifications for largest...
Here we report on the results of WEBT photo-polarimetric campaign targeting blazar S5~0716+71, organized in March 2014 to monitor source simultaneously BVRI and near IR filters. The resulted an unprecedented dataset spanning $\sim 110$\,h nearly continuous, multi-band observations, including two sets densely sampled polarimetric data mainly R filter. During campaign, displayed pronounced variability with peak-to-peak variations about $30\%$ "bluer-when-brighter" spectral evolution,...
We analyze 37 months of Kepler photometry 2M 1938+4603, a binary system with pulsating hot subdwarf primary and an M-dwarf companion that shows strong reflection effect. measured the eclipse timings from more than 16 000 secondary eclipses discovered periodic variation in timing signal we ascribe to third body system. also significant long-term trend may be evolutionary effect or hint bodies. Upon assumption is orbiting same plane as primary, establish it must Jupiter-mass object period 416...