Navegação Ciências Exatas e da Terra por Assunto "Binaries: general"

Resultados 1-7 de 7

    • Increasing the census of ultracool dwarfs in wide binary and multiple systems using Dark Energy Survey DR1 and Gaia DR2 data 

      Dal Ponte, Marina; Santiago, Basilio Xavier; DES Collaboration (2020) [Artigo de periódico]
      We present the discovery of 255 binary and 6 multiple system candidates with wide (> 5 arcsec) separation composed by ultracool dwarfs (UCDs) companions to stars, plus nine double ultracool dwarf systems. These systems ...

    • Observational limits on companions to g29-38 

      Kleinman, Scot James; Nather, R. Edward; Winget, Donald Earl; Clemens, J. Christopher; Bradley, Paul A.; Kanaan Neto, Antonio Nemer; Provencal, Judith L.; Claver, C.F.; Watson, Todd K.; Yanagida, K.; Dixson, James S.; Wood, Matthew A.; Sullivan, Denis J.; Meistas, Edmundas G.; Leibowitz, Elia M.; Moskalik, Pawel; Zola, Staszek; Pajdosz, Y.; Krzesinski, Jerzy; Solheim, Jan-Eric; Bruvold, A.; O'Donoghue, Darragh; Katz, M.; Vauclair, Gérard; Dolez, Noël; Chevreton, Michel; Barstow, Martin A.; Kepler, Souza Oliveira; Giovannini Junior, Odilon; Hansen, Carl J.; Kawaler, Steven D. (1994) [Artigo de periódico]
      Recent interest in the variable (DAV) white dwarf G29-38 has been stirred by a tentative report of a radial velocity variation that may be due to an unseen companion. Earlier evidence for a brown dwarf in the system has ...

    • The sdA problem : III. New extremely low-mass white dwarfs and their precursors from Gaia astrometry 

      Pelisoli, Ingrid Domingos; Bell, Keaton; Kepler, Souza Oliveira; Koester, Detlev (2019) [Artigo de periódico]
      The physical nature of the sdA stars – cool hydrogen-rich objects with spectroscopic surface gravities intermediate between main-sequence and canonical-mass white dwarfs – has been elusive since they were found in Sloan ...

    • The sdA problem : II. Photometric and spectroscopic follow-up 

      Pelisoli, Ingrid Domingos; Kepler, Souza Oliveira; Koester, Detlev; Castanheira, Bárbara Garcia; Romero, Alejandra Daniela; Fraga, Luciano (2018) [Artigo de periódico]
      The spectral classification ‘subdwarfA’ (sdA) is given to stars showingH-rich spectra and submain- sequence surface gravities, but effective temperature lower than the zero-age horizontal branch. Their evolutionary origin ...

    • The sdA problem : I. Physical properties 

      Pelisoli, Ingrid Domingos; Kepler, Souza Oliveira; Koester, Detlev (2018) [Artigo de periódico]
      The so-called sdA stars are defined by having H-rich spectra and surface gravities similar to hot subdwarf stars, but effective temperature below the zero-age horizontal branch. Their evolutionary history is an enigma: ...

    • The white dwarf mass–radius relation and its dependence on the hydrogen envelope 

      Romero, Alejandra Daniela; Kepler, Souza Oliveira; Joyce, Simon R. G.; Ramos, Gabriel Lauffer; Córsico, Alejandro Hugo (2019) [Artigo de periódico]
      We present a study of the dependence of the mass–radius relation for DA white dwarf stars on the hydrogen envelope mass and the impact on the value of log g, and thus the determination of the stellar mass. We employ a set ...

    • Very low mass stellar and substellar companions to solar-like stars from MARVELS. I. A low-mass ratio stellar companion to TYC 4110-01037-1 in a 79 day orbit 

      Wisniewski, J.P.; Ge, Jian; Crepp, Justin R.; De Lee, Nathan M.; Eastman, Jason; Esposito, Massimiliano; Fleming, S.W.; Gaudi, B. S.; Ghezzi, Luan; González Hernández, Jonay I.; Lee, Brian L.; Stassun, Keivan G.; Agol, Eric; Allende Prieto, Carlos; Barnes, Rory; Bizyaev, D.; Cargile, Phillip A.; Chang, Liang; Costa, Luiz N. da; Mello, Gustavo Frederico Porto de; Femenía Castellá, B.; Ferreira, Letícia D.; Gary, Bruce L.; Hebb, Leslie; Holtzman, J.A.; Liu, Jian; Ma, Bo; Mack, C. E.; Mahadevan, Suvrath; Maia, Marcio Antonio Geimba; Nguyen, D.C.; Ogando, Ricardo L.C.; Oravetz, Daniel J.; Paegert, Martin; Pan, K.; Pepper, J.; Rebolo, Rafael; Santiago, Basilio Xavier; Schneider, D.P.; Bradley, Alaina C. Shelden; Simmons, Audrey E.; Tofflemire, Benjamin M.; Wan, Xiaoke; Wang, Ji; Zhao, Bo (2012) [Artigo de periódico]
      TYC 4110-01037-1 has a low-mass stellar companion, whose small mass ratio and short orbital period are atypical among binary systems with solar-like (Teff 6000 K) primary stars. Our analysis of TYC 4110-01037-1 reveals it ...