Navegação por Assunto "Asteroseismology"
Resultados 1-16 de 16
-
Asteroseismology of massive ZZ Ceti stars : an updated grid of fully evolutionary models
(2021) [Dissertação]White dwarfs stars are by far the most common outcome of stellar evolution, being the final product of more than 95% of all stars in the Milk Way. During their evolution, the white dwarf stars cross several zones known as ... -
Asteroseismology of pulsating low-mass white dwarf stars
(2024) [Tese]White dwarf stars are the most common final stage of stellar evolution, corresponding to 99% of all stars in the Galaxy. Around 10% of white dwarfs in the solar neighbourhood are low-mass (< 0.45M⊙) objects. In the case ... -
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) [Artigo de periódico]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) [Artigo de periódico]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 ... -
Comparing the asteroseismic properties of pulsating pre-extremely low mass white dwarf and δ Scuti stars
(2018) [Artigo de periódico]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 ... -
Empirical determination of convection parameters in white dwarfs. I. Whole earth telescope obsevations of EC14012-1446
(2012) [Artigo de periódico]We report on an analysis of 308.3 hr of high-speed photometry targeting the pulsating DA white dwarf EC14012-1446. The datawere acquiredwith theWhole Earth Telescope during the 2008 international observing run XCOV26. The ... -
Galactic archaeology with asteroseismology and spectroscopy : red giants observed by CoRoT and APOGEE
(2017) [Artigo de periódico]With the advent of the space missions CoRoT and Kepler, it has recently become feasible to determine precise asteroseismic masses and relative ages for large samples of red giant stars. We present the CoRoGEE dataset, ... -
Kepler and TESS observations of PG 1159-035
(2022) [Artigo de periódico]PG 1159-035 is the prototype of the PG 1159 hot (pre-)white dwarf pulsators. This important object was observed during the Kepler satellite K2 mission for 69 days in 59 s cadence mode and by the TESS satellite for 25 days ... -
Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with TESS : I. Asteroseismology of the GW Virstars RX J2117+3412, HS 2324+3944, NGC 6905, NGC 1501, NGC 2371, and K 1−16
(2021) [Artigo de periódico]Context. The recent arrival of continuous photometric observations of unprecedented quality from space missions has strongly promoted the study of pulsating stars and caused great interest in the stellar astrophysics ... -
Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with TESS : II. Discovery of two new GW Vir stars: TIC 333432673 and TIC 095332541
(2021) [Artigo de periódico]Context. The Transiting Exoplanet Survey Satellite (TESS) mission is revolutionizing the blossoming area of asteroseismology, particularly of pulsating white dwarfs and pre-white dwarfs, thus continuing the impulse of its ... -
Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with TESS : III. Asteroseismology of the DBV star GD 358
(2022) [Artigo de periódico]Context. The collection of high-quality photometric data by space telescopes, such as the completed Kepler mission and the ongoing TESS program, is revolutionizing the area of white-dwarf asteroseismology. Among the different ... -
Pulsating low-mass white dwarfs in the frame of new evolutionary sequences : III. The pre-ELM white dwarf instability strip
(2016) [Artigo de periódico]Context. Many low-mass (M /M <∼ 0.45) and extremely low-mass (ELM, M /M <∼ 0.18−0.20) white-dwarf stars are currently being found in the field of the Milky Way. Some of these stars exhibit long-period gravity-mode (g-mode) ... -
Pulsating low-mass white dwarfs in the frame of new evolutionary sequences : VI. Thin H-envelope sequences and asteroseismology of ELMV stars revisited
(2018) [Artigo de periódico]Context. Some low-mass white-dwarf (WD) stars with H atmospheres currently being detected in our galaxy, show long-period g(gravity)-mode pulsations, and comprise the class of pulsating WDs called extremely low-mass variable ... -
The pulsating helium-atmosphere white dwarfs : I. New DBVs from the Sloan Digital Sky Survey
(2022) [Artigo de periódico]We present a dedicated search for new pulsating helium-atmosphere (DBV) white dwarfs from the Sloan Digital Sky Survey using the McDonald 2.1 m Otto Struve Telescope. In total we observed 55 DB and DBA white dwarfs with ... -
Uncovering the chemical structure of the pulsating low-mass white dwarf SDSS J115219.99+024814.4
(2022) [Artigo de periódico]Pulsating low-mass white dwarf (WD) stars are WDs with stellar masses between 0.30 and 0.45 M⊙ that show photometric variability due to gravity-mode pulsations. Within this mass range, they can harbour both a helium core ... -
Young (α/Fe)-enhanced stars discovered by CoRoT and APOGEE : what is their origin?
(2015) [Artigo de periódico]We report the discovery of a group of apparently young CoRoT red-giant stars exhibiting enhanced [ /Fe] abundance ratios (as determined from APOGEE spectra) with respect to solar values. Their existence is not explained ...
