Browsing Exact and Earth Sciences by Author "Romero, Alejandra Daniela"
Now showing items 1-20 of 35
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Asteroseismological study of massive ZZ Ceti stars with fully evolutionary models
(2013) [Journal article]We present the first asteroseismological study for 42 massive ZZ Ceti stars based on a large set of fully evolutionary carbon–oxygen core DA white dwarf models characterized by a detailed and consistent chemical inner ... -
Asteroseismology of PG 1541 + 651 and BPM 31594 with TESS
(2023) [Journal article]We present the photometric data from TESS for two known ZZ Ceti stars, PG 1541 + 651 and BPM 31594. Before TESS, both objects only had observations from short runs from ground-based facilities, with three and one period ... -
Asteroseismology of ZZ Ceti stars with full evolutionary white dwarf models : II. The impact of AGB thermal pulses on the asteroseismic inferences of ZZ Ceti stars
(2018) [Journal article]Context. The thermally pulsing phase on the asymptotic giant branch (TP-AGB) is the last nuclear burning phase experienced by most low- and intermediate-mass stars. During this phase, the outer chemical stratification above ... -
Asteroseismology of ZZ Ceti stars with fully evolutionary white dwarf models : I. the impact of the uncertainties from prior evolution on the period spectrum
(2017) [Journal article]Context. ZZ Ceti stars are pulsating white dwarfs with a carbon-oxygen core build up during the core helium burning and thermally pulsing Asymptotic Giant Branch phases. Through the interpretation of their pulsation periods ... -
Catalog of magnetic white dwarfs with hydrogen dominated atmospheres
(2023) [Journal article]White dwarfs are excellent research laboratories as they reach temperatures, pressures, and magnetic fields that are unattainable on Earth. To better understand how these three physical parameters interact with each other ... -
A comparative analysis of the observed white dwarf cooling sequence from globular clusters
(2016) [Journal article]We report our study of features at the observed red end of the white dwarf cooling sequences for three Galactic globular clusters: NGC 6397, 47 Tucanae and M 4. We use deep colour– magnitude diagrams constructed from ... -
Comparing the asteroseismic properties of pulsating extremely low-mass pre-white dwarf stars and δ Scuti stars
(2017) [Journal article]We present the first results of a detailed comparison between the pulsation properties of pulsating Extremely Low-Mass pre-white dwarf stars (the pre-ELMV variable stars) and δ Scuti stars. The instability domains of these ... -
Comparing the asteroseismic properties of pulsating pre-extremely low mass white dwarf and δ Scuti stars
(2018) [Journal article]Context. Pulsating extremely low-mass pre-white dwarf stars (pre-ELMV), with masses between ~0.15 M⊙ and ~0.30 M⊙, constitute a new class of variable stars showing g- and possibly p-mode pulsations with periods between 320 ... -
Discovery of 74 new bright ZZ Ceti stars in the first three years of TESS
(2022) [Journal article]We report the discovery of 74 new pulsating DA white dwarf stars, or ZZ Cetis, from the data obtained by the Transiting Exoplanet Survey Satellite mission, from Sectors 1 to 39, corresponding to the first 3 cycles. This ... -
Evidence from K2 for Rapid Rotation in the Descendant of an Intermediate-mass Star
(2017) [Journal article]Using patterns in the oscillation frequencies of a white dwarf observed by K2, we have measured the fastest rotation rate (1.13 ± 0.02 hr) of any isolated pulsating white dwarf known to date. Balmer-line fits to follow-up ... -
Evidence of spectral evolution on the white dwarf sample from the Gaia mission
(2020) [Journal article]Since the Gaia data release 2, several works have been published describing a bifurcation in the observed white dwarf colour−magnitude diagram for GBP−GRP>0. Some possible explanations in the literature include the existence ... -
Four new massive pulsating white dwarfs including an ultramassive DAV
(2017) [Journal article]We report the discovery of four massive (M > 0.8M ) ZZ Ceti white dwarfs, including an ultramassive 1.16M star. We obtained ground-based, time series photometry for 13 white dwarfs from the Sloan Digital Sky Survey Data ... -
Ground-based observation of ZZ Ceti stars and the discovery of four new variables
(2019) [Journal article]We perform ground-based photometric observations of 22 DA white dwarf stars, 10 already known ZZ Cetis and 12 candidates with atmospheric parameters inside the classical instability strip. We report on the discovery of ... -
Measuring the evolutionay rate of cooling of ZZ Ceti
(2013) [Journal article]We have finally measured the evolutionary rate of cooling of the pulsating hydrogen atmosphere (DA) white dwarf ZZ Ceti (Ross 548), as reflected by the drift rate of the 213.13260694 s period. Using 41 yr of time-series ... -
New evolutionary sequences for hot h-deficient white dwarfs on the basis of a full account of progenitor evolution
(2009) [Journal article]We present full evolutionary calculations appropriate for the study of hot hydrogen-deficient DO white dwarfs, PG 1159 stars, and DB white dwarfs. White dwarf sequences are computed for a wide range of stellar masses and ... -
New full evolutionary sequences of H- and He-atmosphere massive white dwarf stars using MESA
(2018) [Journal article]We explore the evolution of hydrogen-rich and hydrogen-deficient white dwarf stars with masses between 1.012 and 1.307M , and initial metallicity of Z = 0.02. These sequences are the result ofmain-sequence stars with masses ... -
New white dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 12
(2016) [Journal article]We report the discovery of 6576 new spectroscopically confirmed white dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 12. We obtain Teff, log g and mass for hydrogen atmospherewhite dwarf stars (DAs) ... -
New white dwarf stars in the Sloan Digital Sky Survey Data Release 10
(2015) [Journal article]We report the discovery of 9088 new spectroscopically confirmed white dwarfs and subdwarfs in the Sloan Digital Sky Survey Data Release 10. We obtain Teff, log g and mass for hydrogen atmosphere white dwarf stars (DAs) and ... -
On the evolutionary status and pulsations of the recently discovered blue large-amplitude pulsators (BLAPs)
(2018) [Journal article]The blue large-amplitude pulsators (BLAPs) constitute a new class of pulsating stars. They are hot stars with effective temperatures of ~30 000K and surface gravities of log g ~ 4.9, that pulsate with periods in the range ... -
Probing the structure of Kepler ZZ Ceti stars with full evolutionary models-based asteroseismology
(2017) [Journal article]We present an asteroseismological analysis of four ZZ Ceti stars observed with the Kepler spacecraft: GD 1212, SDSS J113655.17+040952.6, KIC 11911480, and KIC 4552982, based on a grid of full evolutionary models of DA white ...
