Navegação Ciências Exatas e da Terra por Autor "Sullivan, Denis J."

Resultados 1-20 de 26

    • Amplitude and frequency variability of the pulsating DB white dwarf stars KUV 05134+2605 and PG 1654+160 observed with the Whole Earth Telescope 

      Handler, Gerald; O'Donoghue, Darragh; Muller, M.; Solheim, Jan-Eric; Gonzalez Perez, Jose Miguel; Johannessen, F.; Paparo, Margit; Szeidl, Bela; Virághalmy, Géza; Silvotti, Roberto; Vauclair, Gérard; Dolez, Noël; Pallier, E.; Chevreton, Michel; Kurtz, Donald W.; Bromage, Gordon E.; Cunha, Margarida S.; Ostensen, Roy; Fraga, Luciano; Kanaan Neto, Antonio Nemer; Amorim, André; Giovannini Junior, Odilon; Kepler, Souza Oliveira; Costa, Alex Fabiano Murillo da; Anderson, R.F.; Wood, Matthew A.; Silvestri, Nicole M.; Klumpe, Eric W.; Carlton, Robert F.; Miller, Hugh Richard; McFarland, John P.; Grauer, Albert D.; Kawaler, Steven D.; Riddle, Reed L.; Reed, M. D.; Nather, R. Edward; Winget, Donald Earl; Hill, J.A.; Metcalfe, Travis S.; Mukadam, Anjum Shagufta; Kilic, Mukremin; Watson, Todd K.; Kleinman, Scot James; Nitta, Atsuko; Guzik, Joyce Ann; Bradley, Paul A.; Sekiguchi, Kazuhiro; Sullivan, Denis J.; Sullivan, Terry; Shobbrook, Robert R.; Jiang, Xiaojun; Birch, P.; Ashoka, B.N.; Seetha, S.; Girish, V.; Joshi, Santosh; Dorokhova, Tatyana N.; Dorokhov, N.I.; Akan, Mustafa Can; Meistas, Edmundas G.; Janulis, Rimvydas; Kalytis, Romualdas; Alisauskas, Darius; Anguma, S.K.; Kalebwe, P.C.; Moskalik, Pawel; Ogloza, Waldemar; Stachowski, G.; Pajdosz, Gabriel; Zola, Staszek (2003) [Artigo de periódico]
      We have acquired new time series photometry of the two pulsating DB white dwarf stars KUV 05134+2605 and PG 1654+160 with the Whole Earth Telescope. Additional single-site photometry is also presented. We use all these ...

    • 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) [Artigo de periódico]
      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 ...

    • Constraining the evolution of ZZ Ceti 

      Mukadam, Anjum Shagufta; Kepler, Souza Oliveira; Winget, Donald Earl; Nather, R. Edward; Kilic, Mukremin; Mullally, Fergal; Von Hippel, Theodore A.; Kleinman, Scot James; Nitta, Atsuko; Guzik, Joyce Ann; Bradley, Paul A.; Matthews, Jaymie M.; Sekiguchi, Kazuhiro; Sullivan, Denis J.; Sullivan, Terry; Shobbrook, Robert R.; Birch, P.; Jiang, Xiaojun; Xu, D.W.; Joshi, Santosh; Ashoka, B.N.; Ibbetson, Peter A.; Leibowitz, Elia M.; Ofek, Eran O.; Meistas, Edmundas G.; Janulis, Rimvydas; Alisauskas, Darius; Kalytis, Romualdas; Handler, Gerald; Kilkenny, Dave; O'Donoghue, Darragh; Kurtz, Donald W.; Muller, M.; Moskalik, Pawel; Ogloza, Waldemar; Zola, Staszek; Krzesinski, Jerzy; Johannessen, F.; Gonzalez Perez, Jose Miguel; Solheim, Jan-Eric; Silvotti, Roberto; Bernabei, S.; Vauclair, Gérard; Dolez, Noël; Fu, Jianning Ning; Chevreton, Michel; Manteiga, Minia; Suarez, Olga; Ulla, Ana; Cunha, Margarida S.; Metcalfe, Travis S.; Kanaan Neto, Antonio Nemer; Fraga, Luciano; Costa, Alex Fabiano Murillo da; Giovannini Junior, Odilon; Fontaine, Gilles; Bergeron, Pierre; O'Brien, M. Sean; Sanwal, Divas; Wood, Matthew A.; Ahrens, T.J.; Silvestri, Nicole M.; Klumpe, Eric W.; Kawaler, Steven D.; Riddle, Reed L.; Reed, M. D.; Watson, Todd K. (2003) [Artigo de periódico]
      We report our analysis of the stability of pulsation periods in the DAV star (pulsating hydrogen atmosphere white dwarf ) ZZ Ceti, also called R548. On the basis of observations that span 31 years, we conclude that the ...

    • Discovery of the 'missing' mode in HR 1217 by the Whole Earth Telescope 

      Kurtz, Donald W.; Kawaler, Steven D.; Riddle, Reed L.; Reed, M. D.; Cunha, Margarida S.; Wood, Matthew A.; Silvestri, Nicole M.; Watson, Todd K.; Dolez, Noël; Moskalik, Pawel; Zola, Staszek; Pallier, E.; Guzik, Joyce Ann; Metcalfe, Travis S.; Mukadam, Anjum Shagufta; Nather, R. Edward; Winget, Donald Earl; Sullivan, Denis J.; Sullivan, Terry; Sekiguchi, Kazuhiro; Jiang, Xiaojun; Shobbrook, Robert R.; Ashoka, B.N.; Seetha, S.; Joshi, Santosh; O'Donoghue, Darragh; Handler, Gerald; Mueller, M.; Gonzalez Perez, Jose Miguel; Solheim, Jan-Eric; Johannessen, F.; Ulla, Ana; Kepler, Souza Oliveira; Kanaan Neto, Antonio Nemer; Costa, Alex Fabiano Murillo da; Fraga, Luciano; Giovannini Junior, Odilon; Matthews, Jaymie M.; WET collaboration (2002) [Artigo de periódico]
      HR1217 is a prototypical rapidly oscillating Ap star that has presented a test to the theory of non-radial stellar pulsation. Prior observations showed a clear pattern of five modes with alternating frequency spacings of ...

    • Empirical determination of convection parameters in white dwarfs. I. Whole earth telescope obsevations of EC14012-1446 

      Provencal, Judith L.; Montgomery, Michael Houston; Kanaan Neto, Antonio Nemer; Thompson, S. E.; Dalessio, J.; Shipman, Harry L.; Childers, D.; Clemens, J. Christopher; Rosen, Rachel; Henrique, P.; Bischoff-Kim, Agnès; Strickland, Willie; Chandler, Dean W.; Walter, B.; Watson, Todd K.; Castanheira, Bárbara Garcia; Wang, Siqiu; Handler, Gerald; Wood, Matthew A.; Vennes, S.; Nemeth, Peter; Kepler, Souza Oliveira; Reed, M. D.; Nitta, Atsuko; Kleinman, Scot James; Brown, Tim; Kim, Seung-Lee; Sullivan, Denis J.; Chen, Wen-Ping; Yang, M.; Shih, Chia-You; Jiang, Xiaojun; Sergeev, A.; Maksim, A.; Janulis, Rimvydas; Baliyan, Kiran S.; Vats, Hari Om; Zola, Staszek; Baran, Andrzej; Winiarski, M.; Ogloza, Waldemar; Paparo, Margit; Baran, Andrzej; Bognár, Zsófia; Papics, P.; Kilkenny, Dave; Sefako, R.; Buckley, David A.H.; Loaring, N.; Kniazev, A.; Silvotti, Roberto; Galleti, S.; Nagel, Thorsten; Vauclair, Gérard; Dolez, Noël; Fremy, J. R.; Gonzalez Perez, Jose Miguel; Almenara, J. M.; Fraga, Luciano (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 ...

    • Measuring the evolutionay rate of cooling of ZZ Ceti 

      Mukadam, Anjum Shagufta; Bischoff-Kim, Agnès; Fraser, Oliver; Córsico, Alejandro Hugo; Montgomery, Michael Houston; Kepler, Souza Oliveira; Romero, Alejandra Daniela; Kronberg, M. E.; Winget, K. I.; Falcon, Ross E.; Chandler, Dean W.; Kuehne, J. W.; Sullivan, Denis J.; Reaves, David Earl; Von Hippel, Theodore A.; Mullally, Fergal; Shipman, Harry L.; Thompson, S. E.; Silvestri, Nicole M.; Hynes, R. I. (2013) [Artigo de periódico]
      We have finally measured the evolutionary rate of cooling of the pulsating hydrogen atmosphere (DA) white dwarf ZZ Ceti (Ross 548), as reflected by the drift rate of the 213.13260694 s period. Using 41 yr of time-series ...

    • Measuring the evolution of the most stable optical clock G 117-B15A 

      Kepler, Souza Oliveira; Costa, Jose Eduardo da Silveira; Castanheira, Bárbara Garcia; Winget, Donald Earl; Mullally, Fergal; Nather, R. Edward; Kilic, Mukremin; Von Hippel, Theodore A.; Mukadam, Anjum Shagufta; Sullivan, Denis J. (2005) [Artigo de periódico]
      We report our measurement of the rate of change of period with time (˙P ) for the 215 s periodicity in the pulsating white dwarf G 117-B15A, the most stable optical clock known. After 31 years of observations, we have ...

    • New pulsating db white dwarf stars from the Sloan Digital Sky Survey 

      Nitta, Atsuko; Kleinman, Scot James; Krzesinski, Jerzy; Kepler, Souza Oliveira; Metcalfe, Travis S.; Mukadam, Anjum Shagufta; Mullally, Fergal; Nather, R. Edward; Sullivan, Denis J.; Thompson, S. E.; Winget, Donald Earl (2009) [Artigo de periódico]
      We are searching for new He atmosphere white dwarf pulsators (DBVs) based on the newly found white dwarf stars from the spectra obtained by the Sloan Digital Sky Survey. DBVs pulsate at hotter temperature ranges than their ...

    • New whole earth telescope observations of cd-247599 : steps towards delta scuti star seismology 

      Handler, Gerald; Pikall, H.; O'Donoghue, Darragh; Buckley, David A.H.; Vauclair, Gérard; Chevreton, Michel; Giovannini Junior, Odilon; Kepler, Souza Oliveira; Goode, P.R.; Provencal, Judith L.; Wood, Matthew A.; Clemens, J. Christopher; O'Brien, M. Sean; Nather, R. Edward; Winget, Donald Earl; Kleinman, Scot James; Kanaan Neto, Antonio Nemer; Watson, Todd K.; Nitta, Atsuko; Montgomery, Michael Houston; Klumpe, Eric W.; Bradley, Paul A.; Sullivan, Denis J.; Wu, K.; Marar, T.M. Krishnan; Seetha, S.; Ashoka, B.N.; Mahra, H.S.; Bhat, B.C.; Babu, V.C.; Leibowitz, Elia M.; Hemar, Shirley; Ibbetson, Peter A.; Mashal, E.; Meistas, Edmundas G.; Dziembowski, W.A.; Pamyantnykh, A.A.; Moskalik, Pawel; Zola, Staszek; Pajdosz, Gabriel; Krzesinski, Jerzy; Solheim, Jan-Eric; Bard, S.; Massarand, C.M.; Breger, M.; Gelbmann, M.J.; Paunzen, E.; North, P. (1997) [Artigo de periódico]
      92 h of new Whole Earth Telescope observations have been acquired for the δ Scuti star CD -24 7599. All the seven pulsation modes reported by Handler et al. are confirmed. However, significant amplitude variations which ...

    • Nonradial pulsation of the unevolved hot (gamma) scuti star cd-24 7599 discovered with the whole earth telescope 

      Handler, Gerald; Breger, M.; Sullivan, Denis J.; Peet, A.J. van der; Clemens, J. Christopher; O'Donoghue, Darragh; Chen, A.-L.; Kanaan Neto, Antonio Nemer; Sterken, C.; Claver, C.F.; Krisciunas, K.; Kleinman, Scot James; Wickramasinghe, D.T.; Wills, Beverley J.; Provencal, Judith L.; Nather, R. Edward; Winget, Donald Earl; Watson, Todd K.; Barstow, Martin A.; Buckley, David A.H. (1996) [Artigo de periódico]
      We report a frequency analysis of the δ Scuti star CD-24°7599 and the discovery that it pulsates nonradially with at least 7 frequencies between 27.01 and 38.11 cycles per day (312 to 441 μHz). These results are based on ...

    • Normal modes and discovery of high-order cross-frequencies in the DBV white dwarf GD 358 

      Vuille, F.; O'Donoghue, Darragh; Buckley, David A.H.; Massacand, C.N.; Solheim, Jan-Eric; Bard, S.; Vauclair, Gérard; Giovannini Junior, Odilon; Kepler, Souza Oliveira; Kanaan Neto, Antonio Nemer; Provencal, Judith L.; Wood, Matthew A.; Clemens, J. Christopher; Kleinman, Scot James; O'Brien, M. Sean; Nather, R. Edward; Winget, Donald Earl; Nitta, Atsuko; Klumpe, Eric W.; Montgomery, Michael Houston; Watson, Todd K.; Bradley, Paul A.; Sullivan, Denis J.; Wu, K.; Marar, T.M. Krishnan; Seetha, S.; Ashoka, B.N.; Mahra, H.S.; Bhat, B.C.; Babu, V.C.; Leibowitz, Elia M.; Hemar, Shirley; Ibbetson, Peter A.; Mashal, E.; Meistas, Edmundas G.; Moskalik, Pawel; Zola, Staszek; Krzesinski, Jerzy; Pajdosz, Gabriel (2000) [Artigo de periódico]
      We present a detailed mode identification performed on the 1994 Whole Earth Telescope (WET) run on GD 358. The results are compared with that obtained for the same star from the 1990 WET data. The two temporal spectra show ...

    • 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 ...

    • Observations of the pulsating white dwarf G 185-32 

      Castanheira, Bárbara Garcia; Kepler, Souza Oliveira; Moskalik, Pawel; Zola, Staszek; Pajdosz, Gabriel; Krzesinski, Jerzy; O'Donoghue, Darragh; Katz, M.; Buckley, David A.H.; Vauclair, Gérard; Dolez, Noël; Chevreton, Michel; Barstow, Martin A.; Kanaan Neto, Antonio Nemer; Giovannini Junior, Odilon; Provencal, Judith L.; Kawaler, Steven D.; Clemens, J. Christopher; Nather, R. Edward; Winget, Donald Earl; Watson, Todd K.; Yanagida, K.; Dixson, James S.; Hansen, Carl J.; Bradley, Paul A.; Wood, Matthew A.; Sullivan, Denis J.; Kleinman, Scot James; Meistas, Edmundas G.; Solheim, Jan-Eric; Bruvold, A.; Leibowitz, Elia M.; Mazeh, Tsevi; Koester, D.; Montgomery, Michael Houston (2004) [Artigo de periódico]
      We observed the pulsating hydrogen atmosphere white dwarf G 185–32 with the Whole Earth Telescope in 1992. We report on a weighted Fourier transform of the data detecting 18 periodicities in its light curve. Using the ...

    • 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) [Artigo de periódico]
      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 ...

    • The everchanging pulsating white dwarf GD358 

      Kepler, Souza Oliveira; Nather, R. Edward; Winget, Donald Earl; Nitta, Atsuko; Kleinman, Scot James; Metcalfe, Travis S.; Sekiguchi, Kazuhiro; Jiang, Xiaojun; Sullivan, Denis J.; Sullivan, Terry; Janulis, Rimvydas; Meistas, Edmundas G.; Kalytis, Romualdas; Krzesinski, Jerzy; Ogloza, Waldemar; Zola, Staszek; O'Donoghue, Darragh; Romero-Colmenero, Encarni; Martinez, Peter; Dreizler, Stefan; Deetjen, Jochen L.; Nagel, Thorsten; Schuh, Sonja L.; Vauclair, Gérard; Fu, Jianning Ning; Chevreton, Michel; Solheim, Jan-Eric; Gonzalez Perez, Jose Miguel; Johannessen, F.; Kanaan Neto, Antonio Nemer; Costa, Jose Eduardo da Silveira; Costa, Alex Fabiano Murillo da; Wood, Matthew A.; Silvestri, Nicole M.; Ahrens, T.J.; Jones, Aaron Kyle; Collins, A.E.; Boyer, M.; Shaw, James Scott; Mukadam, Anjum Shagufta; Klumpe, Eric W.; Larrison, Jesse; Kawaler, Steven D.; Riddle, Reed L.; Ulla, Ana; Bradley, Paul A. (2003) [Artigo de periódico]
      We report 323 hours of nearly uninterrupted time series photometric observations of the DBV star GD 358 acquired with the Whole Earth Telescope (WET) during May 23rd to June 8th, 2000. We acquired more than 232 000 independent ...

    • The pulsation modes of the pre-white dwarf PG 1159-035 

      Costa, Jose Eduardo da Silveira; Kepler, Souza Oliveira; Winget, Donald Earl; O'Brien, M. Sean; Kawaler, Steven D.; Costa, Alex Fabiano Murillo da; Giovannini Junior, Odilon; Kanaan Neto, Antonio Nemer; Mukadam, Anjum Shagufta; Mullally, Fergal; Nitta, Atsuko; Provencal, Judith L.; Shipman, Harry L.; Wood, Matthew A.; Ahrens, T.J.; Grauer, Albert D.; Kilic, Mukremin; Bradley, Paul A.; Sekiguchi, Kazuhiro; Crowe, Richard A.; Jiang, Xiaojun; Sullivan, Denis J.; Sullivan, Terry; Rosen, Rachel; Clemens, J. Christopher; Janulis, Rimvydas; O'Donoghue, Darragh; Ogloza, Waldemar; Baran, Andrzej; Silvotti, Roberto; Marinoni, S.; Vauclair, Gérard; Dolez, Noël; Chevreton, Michel; Dreizler, Stefan; Schuh, Sonja L.; Deetjen, Jochen L.; Nagel, Thorsten; Solheim, Jan-Eric; Gonzalez Perez, Jose Miguel; Ulla, Ana; Barstow, Martin A.; Burleigh, Matt; Good, Simon A.; Metcalfe, Travis S.; Kim, Seung-Lee; Lee, H.; Sergeev, A.; Akan, Mustafa Can; Cakirli, Ö; Paparo, Margit; Virághalmy, Géza; Ashoka, B.N.; Handler, Gerald; Hürkal, Özlem; Johannessen, F.; Kleinman, Scot James; Kalytis, Romualdas; Krzesinski, Jerzy; Klumpe, Eric W.; Larrison, Jesse; Lawrence, T.; Meistas, Edmundas G.; Martinez, Peter; Nather, R. Edward; Fu, Jianning Ning; Pakstiene, Erika; Rosen, R.; Romero-Colmenero, Encarni; Riddle, Reed L.; Seetha, S.; Silvestri, Nicole M.; Vuckovic, Maja; Warner, B.; Zola, Staszek; Althaus, Leandro Gabriel; Córsico, Alejandro Hugo; Montgomery, Michael Houston (2008) [Artigo de periódico]
      Context. PG 1159-035, a pre-white dwarf with Teff ~_140 000 K, is the prototype of both two classes: the PG 1159 spectroscopic class and the DOV pulsating class. Previous studies of PG 1159-035 photometric data obtained ...

    • The pulsations of PG 1351+489 

      Redaelli, Maurício; Kepler, Souza Oliveira; Costa, Jose Eduardo da Silveira; Winget, Donald Earl; Handler, Gerald; Castanheira, Bárbara Garcia; Kanaan Neto, Antonio Nemer; Fraga, Luciano; Henrique, P.; Giovannini Junior, Odilon; Provencal, Judith L.; Shipman, Harry L.; Dalessio, J.; Thompson, S. E.; Mullally, Fergal; Brewer, M. M.; Childers, D.; Oksala, M. E.; Rosen, Rachel; Wood, Matthew A.; Reed, M. D.; Walter, B.; Strickland, Willie; Chandler, Dean W.; Watson, Todd K.; Nather, R. Edward; Montgomery, Michael Houston; Bischoff-Kim, Agnès; Hansen, Carl J.; Nitta, Atsuko; Kleinman, Scot James; Claver, C.F.; Brown, Tim; Sullivan, Denis J.; Kim, Seung-Lee; Chen, Wen-Ping; Yang, M.; Shih, Chia-You; Zhang, X; Jiang, Xiaojun; Fu, Jianning Ning; Seetha, S.; Ashoka, B.N.; Marar, T.M. Krishnan; Baliyan, Kiran S.; Vats, Hari Om; Chernyshev, A.V.; Ibbetson, Peter A.; Leibowitz, Elia M.; Hemar, Shirley; Sergeev, A.; Andreev, M.; Janulis, Rimvydas; Meistas, Edmundas G.; Moskalik, Pawel; Pajdosz, Gabriel; Baran, Andrzej; Winiarski, M.; Zola, Staszek; Ogloza, Waldemar; Siwak, Michal; Bognár, Zsófia; Solheim, Jan-Eric; Sefako, R.; Buckley, David A.H.; O'Donoghue, Darragh; Nagel, Thorsten; Silvotti, Roberto; Bruni, I.; Fremy, J. R.; Vauclair, Gérard; Chevreton, Michel; Dolez, Noël; Pfeiffer, Ben; Barstow, Martin A.; Creevey, o; Kawaler, Steven D.; Clemens, J. Christopher (2011) [Artigo de periódico]
      PG 1351+489 is one of the 20DBVs – pulsating helium-atmospherewhite dwarf stars – known and has the simplest power spectrum for this class of star, making it a good candidate to study cooling rates. We report accurate ...

    • Thirty-five new pulsating DA white dwarf stars 

      Mukadam, Anjum Shagufta; Mullally, Fergal; Nather, R. Edward; Winget, Donald Earl; Von Hippel, Theodore A.; Kleinman, Scot James; Nitta, Atsuko; Krzesinski, Jerzy; Kepler, Souza Oliveira; Kanaan Neto, Antonio Nemer; Koester, Detlev; Sullivan, Denis J.; Homeier, Derek; Thompson, S. E.; Reaves, David Earl; Cotter, C.; Slaughter, D.; Brinkmann, Jon (2004) [Artigo de periódico]
      We present 35 new pulsating DA (hydrogen atmosphere) white dwarf stars discovered from the Sloan Digital Sky Survey (SDSS) and the Hamburg Quasar Survey (HQS). We have acquired high-speed time series photometry of preselected ...

    • Understanding the cool DA white dwarf pulsator 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.; Nitta, Atsuko; Dixson, James S.; Wood, Matthew A.; Grauer, Albert D.; Hine, B.P.; Fontaine, Gilles; Liebert, James; Sullivan, Denis J.; Wickramasinghe, D.T.; Achilleos, Nicholas; Marar, T.M. Krishnan; Seetha, S.; Ashoka, B.N.; Meistas, Edmundas G.; Leibowitz, Elia M.; Moskalik, Pawel; Krzesinski, Jerzy; Solheim, Jan-Eric; Bruvold, A.; O'Donoghue, Darragh; Kurtz, Donald W.; Warner, B.; Martinez, Peter; Vauclair, Gérard; Dolez, Noël; Chevreton, Michel; Barstow, Martin A.; Kepler, Souza Oliveira; Giovannini Junior, Odilon; Augusteijn, T.; Hansen, Carl J.; Kawaler, Steven D. (1998) [Artigo de periódico]
      The white dwarfs are promising laboratories for the study of cosmochronology and stellar evolution. Through observations of the pulsating white dwarfs, we can measure their internal structures and compositions, critical ...

    • A Whole Earth Telescope campaign on the pulsating subdwarf B binary system PG 1336-018 (NY Vir) 

      Kilkenny, Dave; Reed, M. D.; O'Donoghue, Darragh; Kawaler, Steven D.; Mukadam, Anjum Shagufta; Kleinman, Scot James; Nitta, Atsuko; Metcalfe, Travis S.; Provencal, Judith L.; Watson, Todd K.; Sullivan, Denis J.; Sullivan, Terry; Shobbrook, Robert R.; Jiang, Xiaojun; Joshi, Santosh; Ashoka, B.N.; Seetha, S.; Leibowitz, Elia M.; Ibbetson, Peter A.; Mendelson, Haim; Meistas, Edmundas G.; Kalytis, Romualdas; Alisauskas, Darius; Martinez, Peter; Van Wyk, Francois; Stobie, Robert S.; Marang, Fred; Zola, Staszek; Krzesinski, Jerzy; Ogloza, Waldemar; Moskalik, Pawel; Silvotti, Roberto; Piccioni, Adalberto; Vauclair, Gérard; Dolez, Noël; Chevreton, Michel; Dreizler, Stefan; Schuh, Sonja L.; Deetjen, Jochen L.; Solheim, Jan-Eric; Gonzalez Perez, Jose Miguel; Ulla, Ana; Ostensen, Roy; Manteiga, Minia; Suarez, Olga; Burleigh, Matt; Kepler, Souza Oliveira; Kanaan Neto, Antonio Nemer; Giovannini Junior, Odilon (2003) [Artigo de periódico]
      We present results from a multisite (‘Whole Earth Telescope’) photometric campaign on PG 1336−018, the close eclipsing binary system containing a pulsating subdwarf B (sdB) star. The main part of the campaign (1999 April) ...