Bi-site observation of the DA type pulsating white dwarf G255-2 and a preliminary astro-seismological analysis

In this paper, we publish the Chinese-French bi-site high-accuracy photoelectric observations of the DA type pulsating white dwarf G 255-2 made in 1995 and 1997. After careful data reduction, we make a multi-frequency analysis, and determine its eigen frequencies and modes. In connection with the theoretical model of white dwarfs, we make a preliminary astro-seismological analysis.