J. Pascual-Granado
A5075026705- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Chaos control and synchronization
- Statistical and numerical algorithms
- Image and Signal Denoising Methods
- Pulsars and Gravitational Waves Research
- Complex Systems and Time Series Analysis
- Dark Matter and Cosmic Phenomena
- Statistical Mechanics and Entropy
- Particle physics theoretical and experimental studies
- Scientific Research and Discoveries
- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Geological and Geophysical Studies
- Radio Astronomy Observations and Technology
- Neutrino Physics Research
- Blind Source Separation Techniques
- Seismology and Earthquake Studies
Instituto de Astrofísica de Andalucía
2015-2024
Jagiellonian University
2021
North-West University
2021
Consejo Superior de Investigaciones Científicas
2019-2021
Calar Alto Observatory
2018
Abstract The Astropy Project supports and fosters the development of open-source openly developed Python packages that provide commonly needed functionality to astronomical community. A key element is core package astropy , which serves as foundation for more specialized projects packages. In this article, we summarize features in recent major release, version 5.0, updates on Project. We then discuss supporting a broader ecosystem interoperable packages, including connections with several...
The Kepler spacecraft is providing time series of photometric data with micromagnitude precision for hundreds A-F type stars. We present a first general characterization the pulsational behaviour stars as observed in light curves sample 750 candidate propose three main groups to describe variety pulsating stars: gamma Dor, delta Sct, and hybrid assign 63% our one groups, identify remaining part rotationally modulated/active stars, binaries, different spectral type, or that show no clear...
Delta Scuti ($\delta$ Sct) stars are intermediate-mass pulsators, whose intrinsic oscillations have been studied for decades. However, modelling their pulsations remains a real theoretical challenge, thereby even hampering the precise determination of global stellar parameters. In this work, we used space photometry observations eclipsing binaries with $\delta$ Sct component to obtain reliable physical parameters and oscillation frequencies. Using that information, derived an observational...
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...
The design and construction of CARMENES has been presented at previous SPIE conferences. It is a next-generation radial-velocity instrument the 3.5m telescope Calar Alto Observatory, which was built by consortium eleven Spanish German institutions. consists two separate échelle spectrographs covering wavelength range from 0.52 to 1.71μm spec-tral resolution R < 80,000, fed fibers Cassegrain focus telescope. saw "First Light" on Nov 9, 2015. During commissioning initial operation phases, we...
Abstract We present the results of Fermi-Large Area Telescope 10 yr long light curve (LC) modeling selected blazars: six flat-spectrum radio quasars (FSRQs) and five BL Lacertae (BL Lacs), examined in 7, 10, 14 day binning. The LCs power spectral densities (PSDs) were investigated with various methods: Fourier transform, Lomb–Scargle periodogram (LSP), wavelet scalogram, autoregressive moving average (ARMA) process, continuous-time ARMA (CARMA), Hurst exponent ( H ), <?CDATA ${ \mathcal A...
Abstract We present the first analysis of Cepheid stars observed by TESS space mission in Sectors 1–5. Our sample consists 25 pulsators: ten fundamental mode, three overtone and two double-mode classical Cepheids, plus type II seven anomalous Cepheids. The targets were chosen from fields with different stellar densities, both Galactic field Magellanic System. Three have 2 minutes cadence light curves available Science Processing Operations Center: for rest, we prepared custom full-frame...
ABSTRACT We present the first asteroseismic results for δ Scuti and γ Doradus stars observed in Sectors 1 2 of TESS mission. utilize 2-min cadence data a sample 117 to classify their behaviour regarding variability place them Hertzsprung–Russell diagram using Gaia DR2 data. Included within our are eponymous members two pulsator classes, SX Phoenicis. Our pulsating intermediate-mass by also allows us confront theoretical models pulsation driving classical instability strip time show that...
The work reported here demonstrates that it is possible to accurately determine surface gravities of $\delta$ Sct stars using the frequency content from high precision photometry and a measurement parallax. Using sample 10 eclipsing binary systems with component unique star discovered transiting planet, WASP-33, we were able refine $\Delta\nu-\bar\rho$ relation. this relation parallaxes, obtained independent values for masses radii, allowing us calculate without any constraints spectroscopic...
The environment of NGC1052 has recently attracted much attention because the presence low-surface-brightness galaxies (LSBGs) with apparently "exotic" properties, making it a region high interest for detection new objects. We used public deep photometric data from DECaLS to carry out comprehensive search LSBGs over wide 6x6 degrees, equivalent 2x2 Mpc at distance NGC1052. detected 42 r_e > 5 arcsec and mu_g(0) 24 mag/arcsec2, which 20 are previously undetected RCP32 stands extreme...
ABSTRACT We present the results of a systematic search Transiting Exoplanet Survey Satellite (TESS) 2-min cadence data for new rapidly oscillating Ap (roAp) stars observed during Cycle 2 phase its mission. find seven roAp previously unreported as such and analysis further 25 that are already known. Three show multiperiodic pulsations, while all members rotationally variable stars, leading to almost 70 per cent (22) presented being α2 CVn-type stars. targeted observations known chemically...
We report an analysis of the first known Beta Cep pulsator observed by TESS mission, runaway star PHL 346 = HN Aqr. The star, previously as a singly-periodic pulsator, has at least 34 oscillation modes excited, 12 those in g-mode domain and 22 p modes. Analysis archival data implies that amplitude frequency dominant mode stellar radial velocity were variable over time. A binary nature would be inconsistent with inferred ejection from Galactic disc 420 km/s, which is too large to survivable...
We present the results of a systematic search for new rapidly oscillating Ap (roAp) stars using 2-min cadence data collected by Transiting Exoplanet Survey Satellite (TESS) during its Cycle 1 observations. identify 12 roAp stars. Amongst these we discover star with longest pulsation period, another shortest rotation and six multiperiodic variability. In addition to stars, an analysis 44 known observed TESS 1, providing first high-precision homogeneous sample significant fraction The...
ABSTRACT In this work, we aim at constraining the age of young open cluster Melotte 20, known as α Per, using seismic indices. The method consists following steps: (1) Extract frequency content a sample stars in field an cluster. (2) Search for possible regularities spectra δ Sct candidates, different techniques, such Fourier transform, autocorrelation function, histogram differences and échelle diagram. (3) Constrain selected by both physical parameters indices comparing them with grid...
Context. Gaps in time series cause spurious frequencies the power spectra. In light curves of pulsating stars, this hampers identifying theoretical oscillation modes. When these gaps are smaller than total span, commonly used approach to overcome difficulties involves linear interpolation. The original frequency content stars is not preserved resulting series.
Detecting and understanding rotation in stellar interiors is nowadays one of the unsolved problems physics. Asteroseismology has been able to provide insights on for Sun, solar-like stars, compact objects like white dwarfs. However, this still very difficult intermediate-mass stars. These stars are moderate-to-rapid rotators. Rotation splits shifts oscillation modes, which makes spectrum more complex harder interpret. Here we study patterns a sample benchmark $δ$~Sct belonging eclipsing...
Context . Over the last few years, δ Scuti stars have been at center of attention asteroseismology community thanks to derivation seismic indices connected stellar parameters. The statistical analysis wealth data offered by a large space survey such as Transiting Exoplanet Survey Satellite (TESS), identification new stars, and correlation between asteroseismic parameters in resulting sample are therefore utmost interest. Aims goal our study is analyze properties characterize observed TESS...
Using ultra-precise data from space instrumentation we found that the underlying functions of stellar light curves some AF pul- sating stars are non-analytic, and consequently their Fourier expansion is not guaranteed. This result demonstrates periodograms do provide a mathematically consistent estimator frequency content for this kind variable stars. More importantly, constitutes first counterexample against current paradigm which considers any physical process described by contin- uous...
We propose that KIC 1573174 is a quadruple-mode $\delta$ Scuti star with pulsation amplitudes between those of the HADS (high-amplitude Delta star) group and average low-amplitude pulsators. The radial modes detected in this provide unique opportunity to exploit asteroseismic techniques up their limits. Detailed frequency analysis given for light curve from Kepler mission. variation dominated by strongest mode F0 = 7.3975 $\rm{d^{-1}}$, as shown Fourier long cadence data (Q1-Q17, spanning...
It is known that the observed distribution of frequencies in CoRoT and Kepler {\delta} Scuti stars has no parallelism with any theoretical model. Pre-whitening a widespread technique analysis time series gaps from pulsating located classical instability strip such as stars. However, some studies have pointed out this might introduce biases results frequency analysis. This work aims at studying can result pre-whitening asteroseismology. The will depend on intrinsic range periodic nature...
Fractal behaviour, i.e. scale invariance in spatio-temporal dynamics, have been found to describe and model many systems nature, particular fluid mechanics geophysical related geometrical objects, like the convective boundary layer of cumulus cloud fields, topographic landscapes, solar granulation patterns, observational astrophysical time series, light curves pulsating stars. The main interest study fractal properties such physical phenomena lies close relationships they with chaotic...
ABSTRACT Fractal fingerprints have been found recently in the light curves of several δ Scuti stars observed by Convection Rotation and planetary Transits(CoRoT) satellite. This sole fact might pose a problem for detection pulsation frequencies using classical pre-whitening techniques, but it is also potentially rich source information about physical mechanisms associated with stellar variability. Assuming that curve composed superposition oscillation modes fractal background noise, this...
Abstract In this paper, we study the pulsation properties of KIC 3440495 using Kepler and TESS data. A Fourier analysis light curve reveals 24 modes as well 29 frequencies associated with rotation. The rotation frequency is derived to be f rot = 2.322909(2) day −1 , rotational modulation determined caused by starspots. large separation Δ ν 54.5 μ Hz found a transform, autocorrelation function, histogram differences, an échelle diagram. We use estimate refined stellar parameters star v [239,...