High-dispersion observations of H-alpha in the suspected brown dwarf, white dwarf binary system G29-38

Journal Article · Sun Jan 01 00:00:00 EST 1989 · Astron. J.; (United States)

DOI:https://doi.org/10.1086/114967· OSTI ID:6407069

Liebert, J; Saffer, R A; Pilachowski, C A

High-dispersion spectroscopy of the H-alpha absorption line of the cool DA white dwarf G29-38 is reported. This is the star for which a recently detected IR excess has been suggested to be due to a possible brown dwarf companion. Three echelle spectra show no evidence for radial-velocity variations larger than about 1.1 + or - 8.7 km/s and are used to derive a weighted heliocentric radial velocity of 33.7 + or - 4.3 kms/s for the white dwarf. The observations of a sharp absorption-line core restricts the possible rotation of the white dwarf to 40 km/s or less and ensures that any surface magnetic field has a strength of 100,000 G or less. These results make it unlikely that the DA white dwarf has previously been in a cataclysmic variable accretion phase. 18 references.

• Research Organization: Steward Observatory, Tucson, AZ (USA); Kitt Peak National Observatory, Tucson, AZ (USA)
• OSTI ID: 6407069
• Journal Information: Astron. J.; (United States), Vol. 97
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BINARY STARS
BALMER LINES
ABSORPTION SPECTRA
DWARF STARS
ERUPTIVE VARIABLE STARS
INFRARED SPECTRA
MAGNETIC FIELDS
MASS
RADIAL VELOCITY
ROTATION
SPECTROSCOPY
STAR ACCRETION
STAR MODELS
VARIATIONS
WHITE DWARF STARS
MATHEMATICAL MODELS
MOTION
SPECTRA
STAR EVOLUTION
STARS
VARIABLE STARS
VELOCITY
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources