Thirty-five new pulsating DA white dwarf stars

• Main Author: Mukadam, Anjum Shagufta
• Publication Date: 2004
• Other Authors: 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
• Format: Article
• Language: eng
• Source: Repositório Institucional da UFRGS
• Download full: http://hdl.handle.net/10183/108916
• topic: Atmosferas estelares; Fotometria estelar; Pulsacoes estelares; Espectros estelares; Estrutura estelar; Estrelas variaveis; Anãs brancas; Stars: imaging; Stars: oscillations; Stars: variables: other; Techniques: photometric; White dwarfs

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 DAwhite dwarfs with a prime focus CCD photometer on the 2.1 m telescope at McDonald Observatory over 15 months. We selected these stars on the basis of prior photometric and spectroscopic observations by the SDSS and HQS. For the homogeneous SDSS sample, we achieve a success rate of 80% for finding new variables at a detection threshold of 0.1%–0.3%. With 35 newly discovered DA variable white dwarfs, we almost double the current sample of 39.