Navegação por Autor "Wesemael, F."

Resultados 1-7 de 7

    • A detection of the evolutionary time scale of the da white dwarf G117-B15A with the Whole Earth Telescope 

      Kepler, Souza Oliveira; Winget, Donald Earl; Nather, R. Edward; Bradley, Paul A.; Grauer, Albert D.; Fontaine, Gilles; Bergeron, Pierre; Vauclair, Gérard; Claver, C.F.; Marar, T.M. Krishnan; Seetha, S.; Ashoka, B.N.; Mazeh, Tsevi; Leibowitz, Elia M.; Dolez, Noël; Chevreton, Michel; Barstow, Martin A.; Clemens, J. Christopher; Kleinman, Scot James; Sansom, A.E.; Tweedy, R.W.; Hine, B.P.; Provencal, Judith L.; Wesemael, F.; Wood, Matthew A.; Brassard, P.; Solheim, Jan-Eric; Emanuelsen, P.-I.; Kanaan Neto, Antonio Nemer; Kepler, Souza Oliveira (1991) [Artigo de periódico]
      We have detected the time rate of change for the main pulsation period of the 13,000 K DA white dwarf G117-B15A, using the Whole Earth Telescope (WET). The observed rate of period change, P = (12.0 ± 3.5) x 10- 15 s s - ...

    • High-speed photometric observations of the pulsating da white dwarf gd 165 

      Bergeron, Pierre; Fontaine, Gilles; Brassard, P.; Lamontagne, R.; Wesemael, F.; Winget, Donald Earl; Nather, R. Edward; Bradley, Paul A.; Claver, C.F.; Clemens, J. Christopher; Kleinman, Scot James; Provencal, Judith L.; Mcgraw, J.T.; Birch, P.; Candy, M.; Buckley, David A.H.; Tripe, P.; Augusteijn, T.; Vauclair, Gérard; Kepler, Souza Oliveira; Kanaan Neto, Antonio Nemer (1993) [Artigo de periódico]
      New high-speed photometric observations ofthe pulsating DA white dwarfGD 165 are presented. The Fourier spectrum ofthe light curve ofGD 165 exhibits two main regions ofpower at 120 and 193 s. The presence of a high-amplitude ...

    • Hot degenerates in the MCT survey. I. MCT 130-1937, a new, color-selected PG 1159 object 

      Demers, Serge; Wesemael, F.; Irwin, Michael John; Fontaine, Gilles; Kepler, Souza Oliveira; Lamontagne, R.; Holberg, J.B. (1990) [Artigo de periódico]
      We report the discovery, in the course of a survey for high-latitude, ultraviolet-excess objects in the southern hemisphere, of a new white dwarf star belonging to the PG 1159 spectroscopic class. A variety of spectroscopic ...

    • Hot degenerates in the montreal-cambridge-tololo survey. II. Two new hybrid white dwarfs, MCT 0128-3846 and MCT 0453-2933 and the nature of the dab stars 

      Bergeron, Pierre; Lamontagne, R.; Fontaine, Gilles; Beauchamp, A.; Demers, Serge; Irwin, Michael John; Holberg, J.B.; Vennes, S.; Kepler, Souza Oliveira; Wesemael, F. (1994) [Artigo de periódico]
      We report the discovery, in the course of a survey for high-latitude, ultraviolet-excess objects in the southern hemisphere, of two new hybrid DAB stars. Both objects exhibit a weak He I λ4471 line superposed onto the usual ...

    • A new hot DA white dwarf in a region of exceptionally low HI density 

      Barstow, Martin A.; Wesemael, F.; Holberg, J.B.; Buckley, David A.H.; Stobie, Robert S.; Mittaz, J.P.D.; Fontaine, Gilles; Rosen, Simon R.; Demers, Serge; Lamontagne, R.; Irwin, Michael John; Bergeron, Pierre; Kepler, Souza Oliveira; Vennes, S. (1994) [Artigo de periódico]
      We report the discovery of the hot DA white dwarf RE 0457- 281 which has the lowest line-of-sight neutral hydrogen column density yet measured. The star was found independently by the ROSAT EUV, Montreal-Cambridge-Tololo ...

    • Whole earth telescope observations and seismological analysis of the cool zz ceti star gd 154 

      Pfeiffer, Ben; Vauclair, Gérard; Dolez, Noël; Chevreton, Michel; Fremy, J. R.; Barstow, Martin A.; Belmonte, J.A.; Kepler, Souza Oliveira; Kanaan Neto, Antonio Nemer; Giovannini Junior, Odilon; Fontaine, Gilles; Bergeron, Pierre; Wesemael, F.; Grauer, Albert D.; Nather, R. Edward; Winget, Donald Earl; Provencal, Judith L.; Clemens, J. Christopher; Bradley, Paul A.; Dixson, James S.; Kleinman, Scot James; Watson, Todd K.; Claver, C.F.; Matzeh, Tsevi; Leibowitz, Elia M.; Moskalik, Pawel (1996) [Artigo de periódico]
      This paper presents the results of high speed photometric observations of the cool variable DA white dwarf (DAV) GD 154 obtained with the Whole Earth Telescope. GD 154 is one of the coolest pulsating DA white dwarfs and ...

    • Whole earth telescope observations of the pulsating hot white dwarf PG 1707+427 

      Kawaler, Steven D.; Potter, E. M.; Vuckovic, Maja; O'Toole, Simon; Clemens, J. Christopher; O'Brien, M. Sean; Grauer, Albert D.; Nather, R. Edward; Moskalik, Pawel; Fontaine, Gilles; Wesemael, F.; Bergeron, Pierre; Vauclair, Gérard; Dolez, Noël; Chevreton, Michel; Kleinman, Scot James; Watson, Todd K.; Barstow, Martin A.; Dind, Z. E.; Sansom, A.E.; Winget, Donald Earl; Kepler, Souza Oliveira; Kanaan Neto, Antonio Nemer; Bradley, Paul A.; Dixson, James S.; Provencal, Judith L.; Bedding, T. R. (2004) [Artigo de periódico]
      We report on the analysis of multisite time-series photometry of the pulsating pre-white dwarf (GW Vir star) PG 1707+427, obtained by the Whole Earth Telescope collaboration. This is the last of the known GW Vir stars ...