A spectroscopically predicted new ZZ Ceti variable - GD 165

Abstract

view Abstract Citations (15) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Spectroscopically Predicted New ZZ Ceti Variable: GD 165 Bergeron, P. ; McGraw, J. T. Abstract The paper reports the discovery that the DA white dwarf GD 165, recently identified as possibly having a brown dwarf companion, is also a ZZ Ceti variable. The analysis of two independent photometric observations shows brightness variations of up to 0.1 mag on time scale of 200-1800 s. Fourier analysis of the light curves indicates that, as is true in general for ZZ Ceti variables, multiple periodicities are present on both nights and the period structure of the star can change on a time scale of 2 days. In the first run, Fourier analysis shows a multiperiodic low-frequency spectrum, while on the second run, the low-frequency spectrum is dominated by an 1800-s period, which is the longest period ever observed in a ZZ Ceti white dwarf. A high-frequency peak of variable amplitude corresponding to a period of 120 s is present in both runs as well. The time variability of the period structure is interpreted as interaction between pulsation modes, as is seen in other ZZ Ceti variables. Publication: The Astrophysical Journal Pub Date: April 1990 DOI: 10.1086/185690 Bibcode: 1990ApJ...352L..45B Keywords: Spectrum Analysis; Stellar Spectra; Variable Stars; White Dwarf Stars; Brown Dwarf Stars; Fourier Analysis; Light Curve; Power Spectra; Stellar Atmospheres; Stellar Temperature; Astrophysics; STARS: INDIVIDUAL ALPHANUMERIC: GD 165; STARS: PULSATION; STARS: WHITE DWARFS full text sources ADS | data products SIMBAD (10)