Browsing by Subject "Rotacao estelar"

Now showing items 1-17 of 17

    • Asteroseismology of a star cooled by neutrino emission : the pulsating pre-white dwarf PG 0122+200 

      O'Brien, M. Sean; Vauclair, Gérard; Kawaler, Steven D.; Watson, Todd K.; Winget, Donald Earl; Nather, R. Edward; Montgomery, Michael Houston; Nitta, Atsuko; Kleinman, Scot James; Sullivan, Denis J.; Jiang, Xiaojun; Marar, T.M. Krishnan; Seetha, S.; Ashoka, B.N.; Bhattacharya, J.; Leibowitz, Elia M.; Hemar, Shirley; Ibbetson, Peter A.; Warner, B.; Van Zyl, L.; Moskalik, Pawel; Zola, Staszek; Pajdosz, Gabriel; Krzesinski, Jerzy; Dolez, Noël; Chevreton, Michel; Solheim, Jan-Eric; Thomassen, T.; Kepler, Souza Oliveira; Giovannini Junior, Odilon; Provencal, Judith L.; Wood, Matthew A.; Clemens, J. Christopher (1998) [Journal article]
      Observation of g-mode pulsations in the variable pre-white dwarf (GW Virginis) stars provides a unique means to probe their interiors and to study the late stages of stellar evolution. Multisite campaigns have in several ...

    • Asteroseismology of RXJ 2117+3412, the hottest pulsating PG 1159 star 

      Vauclair, Gérard; Moskalik, Pawel; Pfeiffer, Ben; Chevreton, Michel; Dolez, Noël; Serre, B.; Kleinman, Scot James; Barstow, Martin A.; Sansom, A.E.; Solheim, Jan-Eric; Belmonte, J.A.; Kawaler, Steven D.; Kepler, Souza Oliveira; Kanaan Neto, Antonio Nemer; Giovannini Junior, Odilon; Winget, Donald Earl; Watson, Todd K.; Nather, R. Edward; Clemens, J. Christopher; Provencal, Judith L.; Dixson, James S.; Yanagida, K.; Nitta, Atsuko; Montgomery, Michael Houston; Klumpe, Eric W.; Bruvold, A.; O'Brien, M. Sean; Hansen, Carl J.; Grauer, Albert D.; Bradley, Paul A.; Wood, Matthew A.; Achilleos, Nicholas; Jiang, Shi Yang; Fu, Jianning Ning; Marar, T.M. Krishnan; Ashoka, B.N.; Meistas, Edmundas G.; Chernyshev, A.V.; Mazeh, Tsevi; Leibowitz, Elia M.; Hemar, Shirley; Krzesinski, Jerzy; Pajdosz, Gabriel; Zola, Staszek (2002) [Journal article]
      The pulsating PG 1159 planetary nebula central star RXJ 2117+3412 has been observed over three successive seasons of a multisite photometric campaign. The asteroseismological analysis of the data, based on the 37 identified ...

    • Chemical abundances in bright giants of the globular cluster M62 (NGC 6266) 

      Yong, David; Alves-Brito, Alan; Da Costa, Gary Stewart; Alonso Garcia, Javier; Karakas, Amanda I.; Pignatari, Marco; Roederer, Ian U.; Aoki, Wako; Fishlock, Cherie K.; Grundahl, Frank; Norris, John E. (2014) [Journal article]
      With the exception of Terzan 5, all the Galactic globular clusters that possess significant metallicity spreads, such as ω Cen and M22, are preferentially the more luminous clusters with extended horizontal branches. Here ...

    • Direct measurement of a secular pulsation period change in the pulsating hot pre-white dwarf PG 1159-035 

      Costa, Jose Eduardo da Silveira; Kepler, Souza Oliveira; Winget, Donald Earl (1999) [Journal article]
      GW Vir (PG 1159[035) is the prototype of the class of multiperiodic, nonradially pulsating hot white dwarfs, and shows a strong pulsation mode at 516 s. All measurements to date of the secular variation of the 516 s pulsation ...

    • High-resolution abundance analysis of red giants in the globular cluster NGC 6522 

      Barbuy, Beatriz; Chiappini, C.C.M.; Cantelli, Elvis William Carvalho; Depagne, Éric; Pignatari, Marco; Hirschi, Raphael; Cescutti, Gabriele; Ortolani, Sergio; Hill, Vanessa; Zoccali, Manuela; Minniti, Dante; Trevisan, Marina; Bica, Eduardo Luiz Damiani; Gómez, Ana (2014) [Journal article]
      Context. The [Sr/Ba] and [Y/Ba] scatter observed in some galactic halo stars that are very metal-poor and in a few individual stars of the oldest known Milky Way globular cluster NGC 6522 have been interpreted as evidence ...

    • Probing the internal rotation of pre-white dwarf stars with asteroseismology : the case of PG 0122+200 

      Córsico, Alejandro Hugo; Althaus, Leandro Gabriel; Kawaler, Steven D.; Bertolami, Marcelo Miguel Miller; García-Berro, Enrique; Kepler, Souza Oliveira (2011) [Journal article]
      We put asteroseismological constraints on the internal rotation profile of theGWVir (PG1159- type) star PG 0122+200. To this end we employ a state-of-the-art asteroseismological model for this star and assess the expected ...

    • Pushing the ground-based limit : 14-μmag photometric precision with the definitive Whole Earth Telescope asteroseismic data set for the rapidly oscillating Ap star HR 1217 

      Kurtz, Donald W.; Cameron, C.; Cunha, Margarida S.; Dolez, Noël; Vauclair, Gérard; Pallier, E.; Ulla, Ana; Kepler, Souza Oliveira; Costa, Alex Fabiano Murillo da; Kanaan Neto, Antonio Nemer; Fraga, Luciano; Giovannini Junior, Odilon; Wood, Matthew A.; Silvestri, Nicole M.; Kawaler, Steven D.; Riddle, Reed L.; Reed, M. D.; Watson, Todd K.; Metcalfe, Travis S.; Mukadam, Anjum Shagufta; Nather, R. Edward; Winget, Donald Earl; Nitta, Atsuko; Kleinman, Scot James; Guzik, Joyce Ann; Bradley, Paul A.; Matthews, Jaymie M.; Sekiguchi, Kazuhiro; Sullivan, Denis J.; Sullivan, Terry; Shobbrook, Robert R.; Jiang, Xiaojun; Birch, P.; Ashoka, B.N.; Seetha, S.; Girish, V.; Joshi, Santosh; Moskalik, Pawel; Zola, Staszek; O'Donoghue, Darragh; Handler, Gerald; Mueller, M.; Gonzalez Perez, Jose Miguel; Solheim, Jan-Eric; Johannessen, F.; Bigot, L. (2005) [Journal article]
      HR1217 is one of the best-studied rapidly oscillating Ap (roAp) stars, with a frequency spectrum of alternating even-and odd-l modes that are distorted by the presence of a strong, global magnetic field. Several recent ...

    • Rotational compact stars in 5-dimensional brane-world gravity 

      Vanazzi, João Vítor Batista (2019) [Dissertation]
      We apply Hartle’s perturbative method for slow rotational stars in 5D Brane-World Gravity theory with Randall-Sundrum geometry of the second kind (RS2). We obtain the modified frame-dragging, monopole and quadrupole ...

    • Spectroscopic binaries in the Solar Twin Planet Search program : from substellar–mass to M dwarf companions 

      Santos, Leonardo Augusto Gonçalves dos; Meléndez, Jorge; Bedell, Megan; Bean, Jacob L.; Spina, Lorenzo; Alves-Brito, Alan; Dreizler, Stefan; Ramírez, Iván; Asplund, Martin (2017) [Journal article]
      Previous studies on the rotation of Sun-like stars revealed that the rotational rates of young stars converge towards a well-defined evolution that follows a power-law decay. It seems, however, that some binary stars do ...

    • The double white dwarf merger progenitors of SDSS J2211+1136 and ZTF J1901+1458 

      Sousa, Manoel Felipe; Coelho, Jaziel Goulart; Araujo, José Carlos Neves de; Kepler, Souza Oliveira; Rueda Hernández, Jorge Armando (2022) [Journal article]
      Double white dwarf (DWD) mergers are possibly the leading formation channel of massive, rapidly rotating, highfield magnetic white dwarfs (HFMWDs). However, a direct link connecting a DWD merger to any observed HFMWD is ...

    • The light curve of the ZZ ceti star G226-29 

      Kepler, Souza Oliveira; Robinson, E.L.; Nather, R. Edward (1983) [Journal article]
      G226-29 is a pulsating DA white dwarf, or ZZ Ceti star. Using 65 hr of high-speed photometry accumulated from 1980 to 1982, we have decomposed the light curve of G226-29 into its component pulsations. There are three ...

    • The solar twin planet search II. A Jupiter twin around a solar twin 

      Bedell, Megan; Meléndez, Jorge; Bean, Jacob L.; Ramírez, Iván; Asplund, Martin; Alves-Brito, Alan; Casagrande, Luca; Dreizler, Stefan; Monroe, TalaWanda Rose; Spina, Lorenzo; Maia, Marcelo Tucci (2015) [Journal article]
      Context. With high-precision radial velocity surveys reaching a su ciently long time baseline, the domain of long-period planet detections has recently opened up. The search for Jupiter-like planets is especially important ...

    • The solar twin planet search : IV. The Sun as a typical rotator and evidence for a new rotational braking law for Sun-like stars 

      Santos, Leonardo Augusto Gonçalves dos; Meléndez, Jorge; Nascimento Júnior, José Dias do; Bedell, Megan; Ramírez, Iván; Bean, Jacob L.; Asplund, Martin; Spina, Lorenzo; Dreizler, Stefan; Alves-Brito, Alan; Casagrande, Luca (2016) [Journal article]
      Context. It is still unclear how common the Sun is when compared to other similar stars in regards to some of its physical properties, such as rotation. Considering that gyrochronology relations are widely used today to ...

    • The solar twin planet search : V. close-in, low-mass planet candidates and evidence of planet accretion in the solar twin HIP 68468 

      Meléndez, Jorge; Bedell, Megan; Bean, Jacob L.; Ramírez, Iván; Asplund, Martin; Dreizler, Stefan; Yan, Hong Liang; Shi, Jianrong; Lind, Karin; Ferraz-Mello, Sylvio; Galarza, Jhon Joel Yana; Santos, Leonardo Augusto Gonçalves dos; Spina, Lorenzo; Maia, Marcelo Tucci; Alves-Brito, Alan; Monroe, TalaWanda Rose; Casagrande, Luca (2017) [Journal article]
      Context. More than two thousand exoplanets have been discovered to date. Of these, only a small fraction have been detected around solar twins, which are key stars because we can obtain accurate elemental abundances ...

    • The temporal changes of the pulsational periods of the pre-white dwarf PG 1159-035 

      Costa, Jose Eduardo da Silveira; Kepler, Souza Oliveira (2008) [Journal article]
      Context. PG 1159-035, a pre-white dwarf with Teff -~ 140 000 K, is the prototype of the PG 1159 spectroscopic class and the DOV pulsating class. Pulsating pre-white dwarf stars evolve rapidly: the effective surface temperature ...

    • Very low mass stellar and substellar companions to solar-like stars from MARVELS. V. A low eccentricity brown dwarf from the driest part of the desert, marvels-6b 

      De Lee, Nathan M.; Ge, Jian; Crepp, Justin R.; Eastman, Jason; Esposito, Massimiliano; Femenía Castellá, B.; Fleming, S.W.; Gaudi, B. S.; Ghezzi, Luan; González Hernández, Jonay I.; Lee, Brian L.; Stassun, Keivan G.; Wisniewski, J.P.; Wood-Vasey, W.M.; Agol, Eric; Allende Prieto, Carlos; Barnes, Rory; Bizyaev, D.; Cargile, Phillip A.; Chang, Liang; Costa, Luiz N. da; Mello, Gustavo Frederico Porto de; 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.; Oravetz, Audrey; Oravetz, Daniel J.; Paegert, Martin; Pan, K.; Pepper, J.; Malanushenko, E.; Malanushenko, V.; Rebolo, Rafael; Santiago, Basilio Xavier; Schneider, D.P.; Bradley, Alaina C. Shelden; Wan, Xiaoke; Wang, Ji; Zhao, Bo (2013) [Journal article]
      We describe the discovery of a likely brown dwarf (BD) companion with a minimum mass of 31.7 ± 2.0 MJup to GSC 03546-01452 from the MARVELS radial velocity survey, which we designate as MARVELS-6b. For reasonable priors, ...

    • Watching ZZ Ceti evolve 

      Mukadam, Anjum Shagufta; Bischoff-Kim, Agnès; Fraser, Oliver; Winget, Donald Earl; Kepler, Souza Oliveira; Sullivan, Denis J.; Reaves, David Earl; Robinson, E.L.; Von Hippel, Theodore A.; Mullally, Fergal; Shipman, Harry L.; Thompson, S. E.; Silvestri, Nicole M.; Hynes, R. I. (2009) [Complete work published in event]