A spectroscopically predicted new ZZ Ceti variable - GD 165

Journal Article · Sun Apr 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/185690· OSTI ID:7041716

Bergeron, P; Mcgraw, J T ^[1]

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1. Steward Observatory, Tucson, AZ (USA)

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. 15 refs.

• OSTI ID: 7041716
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 352; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
BINARY STARS
BRIGHTNESS
DETECTION
DWARF STARS
FOURIER ANALYSIS
OPTICAL PROPERTIES
PHOTOMETRY
PHYSICAL PROPERTIES
STARS
STELLAR ATMOSPHERES
VARIABLE STARS
WHITE DWARF STARS