Navegação Ciências Exatas e da Terra por Assunto "Asterosismologia"

Resultados 21-26 de 26

    • The pulsating helium-atmosphere white dwarfs : I. New DBVs from the Sloan Digital Sky Survey 

      Vanderbosch, Zachary; Hermes, James J.; Winget, Donald Earl; Montgomery, Michael Houston; Bell, Keaton; Nitta, Atsuko; Kepler, Souza Oliveira (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 ...

    • The rate of cooling of the pulsating white dwarf star G117−B15A : a new asteroseismological inference of the axion mass 

      Córsico, Alejandro Hugo; Althaus, Leandro Gabriel; Bertolami, Marcelo Miguel Miller; Romero, Alejandra Daniela; García-Berro, Enrique; Isern, J.; Kepler, Souza Oliveira (2012) [Artigo de periódico]

    • The solar twin planet search : the age-chromospheric activity relation 

      Lorenzo-Oliveira, Diego; Freitas, Fabrício Catani de; Meléndez, Jorge; Bedell, Megan; Ramírez, Iván; Bean, Jacob L.; Asplund, Martin; Spina, Lorenzo; Dreizler, Stefan; Alves-Brito, Alan; Casagrande, Luca (2018) [Artigo de periódico]
      Context. It is well known that the magnetic activity of solar-type stars decreases with age, but it is widely debated in the literature whether there is a smooth decline or if there is an early sharp drop until 1–2 Gyr ...

    • Two new pulsating low-mass pre-white dwarfs or SX Phoenicis stars? 

      Corti, Mariela Alejandra; Kanaan Neto, Antonio Nemer; Córsico, Alejandro Hugo; Kepler, Souza Oliveira; Althaus, Leandro Gabriel; Koester, Detlev; Sánchez Arias, J. P. (2016) [Artigo de periódico]
      Context. The discovery of pulsations in low-mass stars opens an opportunity to probe their interiors and determine their evolution by employing the tools of asteroseismology. Aims. We aim to analyse high-speed photometry ...

    • Uncovering the chemical structure of the pulsating low-mass white dwarf SDSS J115219.99+024814.4 

      Romero, Alejandra Daniela; Ramos, Gabriel Lauffer; Istrate, Alina G.; Parsons, Steven (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? 

      Chiappini, C.C.M.; Anders, Friedrich; Rodrigues, Thaise da Silva; Miglio, Andrea; Montalbán, Josefina; Mosser, Benoît; Girardi, Leo Alberto; Valentini, Marica; Noels, Arlette; Morel , Thierry; Minchev, Ivan; Steinmetz, M.; Santiago, Basilio Xavier; Schultheis, Mathias; Martig, Marie; Costa, Luiz N. da; Maia, Marcio Antonio Geimba; Allende Prieto, Carlos; Assis Peralta, R. de; Hekker, Saskia; Themeßl, Nathalie; Kallinger, Thomas; Garcia, Rafael A.; Mathur, Savita; Baudin, Frederic; Beers, T.C.; Cunha, Katia; Harding, Paul; Holtzman, J.A.; Majewski, Steven Raymond; Mészáros, S.; Nidever, D.L.; Pan, K.; Schiavon, Ricardo P.; Shetrone, M.; Schneider, D.P.; Stassun, Keivan G. (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 ...