• Análise física de curvas de luz de estrelas anãs brancas e pré-anãs brancas pulsantes 

      Costa, Jose Eduardo da Silveira (2004) [Tese]
      As estrelas anãs brancas e pré-anãs brancas pulsantes apresentam pulsações não-radiais, multiperíodicas. Os períodos dos modos de pulsação dependem de parâmetros físicos da estrela, como a massa, a temperatura efetiva da ...
    • Asteroseismological measurements on PG 1159-035, the prototype of the GW Virginis variable stars 

      Córsico, Alejandro Hugo; Althaus, Leandro Gabriel; Kepler, Souza Oliveira; Costa, Jose Eduardo da Silveira; Miller Bertolami, Marcelo Miguel (2008) [Artigo de periódico]
      Aims. An asteroseismological study of PG 1159−035, the prototype of the GW Vir variable stars, has been performed on the basis of detailed and full PG1159 evolutionary models presented by Miller Bertolami & Althaus (2006, ...
    • Asteroseismology of massive ZZ Ceti stars : an updated grid of fully evolutionary models 

      Klippel, Theylor Schumacher (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 the dov star PG 1159-035 with the Whole Earth Telescope 

      Winget, Donald Earl; Hansen, Carl J.; Fontaine, Gilles; Achilleos, Nicholas; Wickramasinghe, D.T.; Marar, T.M. Krishnan; Seetha, S.; Ashoka, B.N.; O'Donoghue, Darragh; Warner, B.; Kurtz, Donald W.; Buckley, David A.H.; Brickhill, J.; Vauclair, Gérard; Dolez, Noël; Chevreton, Michel; Barstow, Martin A.; Solheim, Jan-Eric; Kanaan Neto, Antonio Nemer; Hine, B.P.; Grauer, Albert D.; Frueh, M.L.; Claver, C.F.; Wood, Matthew A.; Bradley, Paul A.; Kleinman, Scot James; Provencal, Judith L.; Clemens, J. Christopher; Nather, R. Edward (1991) [Artigo de periódico]
      We report the results from 264.1 hr of nearly continuous time-series photometry on the pulsating pre-white dwarf star (DOV) PG 1159-035. The high-resolution power spectrum of this data set is dominated by power in the range ...
    • 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 

      De Gerónimo, Francisco Cesar; Althaus, Leandro Gabriel; Córsico, Alejandro Hugo; Romero, Alejandra Daniela; Kepler, Souza Oliveira (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 

      De Gerónimo, Francisco Cesar; Althaus, Leandro Gabriel; Córsico, Alejandro Hugo; Romero, Alejandra Daniela; Kepler, Souza Oliveira (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 extremely low-mass pre-white dwarf stars and δ Scuti stars 

      Sánchez Arias, J. P.; Córsico, Alejandro Hugo; Romero, Alejandra Daniela; Althaus, Leandro Gabriel (2017) [Artigo de periódico]
      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 

      Sánchez Arias, J. P.; Romero, Alejandra Daniela; Córsico, Alejandro Hugo; Pelisoli, Ingrid Domingos; Antoci, Victoria L.; Kepler, Souza Oliveira; Althaus, Leandro Gabriel; Corti, Mariela Alejandra (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 ...
    • Determinação dos modos de pulsação da anã branca pulsante G 185-32 

      Castanheira, Bárbara Garcia (2003) [Dissertação]
      Estrelas anãs brancas são o final evolutivo de quase 98% de todas as estrelas; após a perda de massa durante as fases de gigante e supergigante, elas vão se tornar anãs brancas. Nosso trabalho é estudar a estrutura das ...
    • Discovery of 74 new bright ZZ Ceti stars in the first three years of TESS 

      Romero, Alejandra Daniela; Kepler, Souza Oliveira; Hermes, James J.; Amaral, Larissa Antunes; Uzundag, Murat; Bognár, Zsófia; Bell, Keaton; Vanwyngarden, Madison; Baran, Andy; Pelisoli, Ingrid Domingos; Rosa, Gabriela Oliveira da; Koester, Detlev; Klippel, Theylor Schumacher; Fraga, Luciano; Bradley, Paul A.; Vuckovic, Maja; Heintz, Tyler M.; Reding, Joshua S.; Kaiser, B. C.; Charpinet, Stéphane (2022) [Artigo de periódico]
      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 ...
    • Eleven new DA white dwarf variable stars from the Sloan Digital Sky Survey 

      Mullally, Fergal; Thompson, S. E.; Castanheira, Bárbara Garcia; Winget, Donald Earl; Kepler, Souza Oliveira; Eisenstein, D.J.; Kleinman, Scot James; Nitta, Atsuko (2005) [Artigo de periódico]
      We report the discovery of 11 new variable DAwhite dwarf (ZZ Ceti) stars. Candidates were selected by deriving temperatures from model fits to spectra obtained from the Sloan Digital Sky Survey (SDSS). We also find objects ...
    • Evidence from K2 for Rapid Rotation in the Descendant of an Intermediate-mass Star 

      Hermes, James J.; Kawaler, Steven D.; Romero, Alejandra Daniela; Kepler, Souza Oliveira; Tremblay, Pier-Emmanuel; Bell, Keaton; Dunlap, Bart; Montgomery, Michael Houston; Gänsicke, Boris; Clemens, J. Christopher; Dennihy, Erik D.; Redfield, Seth (2017) [Artigo de periódico]
      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 ...
    • Galactic archaeology with asteroseismology and spectroscopy : red giants observed by CoRoT and APOGEE 

      Anders, Friedrich; Santiago, Basilio Xavier; Zasowski, G. (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 

      Rosa, Gabriela Oliveira da; Kepler, Souza Oliveira; Córsico, Alejandro Hugo; Costa, Jose Eduardo da Silveira; Hermes, James J.; Kawaler, Steven D.; Bell, Keaton; Montgomery, Michael Houston; Provencal, Judith L.; Winget, Donald Earl; Handler, Gerald; Dunlap, Bart; Clemens, J. Christopher; Uzundag, Murat (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 ...
    • Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18 

      Anders, Friedrich; Santiago, Basilio Xavier; Enke, Harry (2019) [Artigo de periódico]
      Combining the precise parallaxes and optical photometry delivered by Gaia’s second data release with the photometric catalogues of Pan-STARRS1, 2MASS, and AllWISE, we derived Bayesian stellar parameters, distances, and ...
    • Probing the structure of Kepler ZZ Ceti stars with full evolutionary models-based asteroseismology 

      Romero, Alejandra Daniela; Córsico, Alejandro Hugo; Castanheira, Bárbara Garcia; De Gerónimo, Francisco Cesar; Kepler, Souza Oliveira; Koester, Detlev; Kawka, Adela; Althaus, Leandro Gabriel; Hermes, James J.; Bonatto, Charles Jose; Gianninas, Alexandros (2017) [Artigo de periódico]
      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 ...
    • 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 

      Córsico, Alejandro Hugo; Uzundag, Murat; Kepler, Souza Oliveira; Althaus, Leandro Gabriel; Silvotti, Roberto; Baran, Andrzej; Vuckovic, Maja; Werner, Klaus; Bell, Keaton; Higgins, Michael (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 

      Uzundag, Murat; Córsico, Alejandro Hugo; Kepler, Souza Oliveira; Althaus, Leandro Gabriel; Werner, Klaus; Reindl, Nicole; Bell, Keaton; Higgins, Michael; Rosa, Gabriela Oliveira da; Vuckovic, Maja; Istrate, Alina G. (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 

      Córsico, Alejandro Hugo; Uzundag, Murat; Kepler, Souza Oliveira; Silvotti, Roberto; Althaus, Leandro Gabriel; Koester, Detlev; Baran, Andrzej; Bell, Keaton; Bischoff-Kim, Agnès; Hermes, James J.; Kawaler, Steven D.; Provencal, Judith L.; Winget, Donald Earl; Montgomery, Michael Houston; Bradley, Paul A.; Kleinman, Scot James; Nitta, Atsuko (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 

      Córsico, Alejandro Hugo; Althaus, Leandro Gabriel; Serenelli, Aldo M.; Kepler, Souza Oliveira; Jeffery, C. Simon; Corti, Mariela Alejandra (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) ...