TY - GEN
T1 - The importance of spectroscopic binary systems for the LB phenomenon
AU - Paunzen, Ernst
AU - Iliev, Ilian
AU - Barzova, Ina S.
AU - Heiter, Ulrike
AU - Kamp, Inga
AU - Claret, Antonio
N1 - Publication start page : 259
Host publication data : Tidal Evolution and Oscillations in Binary Stars: Third Granada Workshop on Stellar Structure, Proceedings of the conference held 16-18 May, 2004 in Granada, Spain
PY - 2005
Y1 - 2005
N2 - We present high-resolution spectroscopic observations of the four LB type spectroscopic binary systems HD 64491, HD 84948, HD 141851 and HD 171948. This group of objects comprise of nonmagnetic, metal-weak, Population I, late B- to early F-type stars. For HD 64491 and HD 141851, estimates of the orbital period were derived. Whereas for the other two systems, detailed abundances and orbital elements are presented. The Hipparcos data reveal that the Galactic space motions of both systems are typical of those of Population I objects. The photometric data from the Hipparcos mission confirm the pulsation previously discovered for HD 84948 with a period of about 110 minutes and a V-amplitude of about 14 mmag. For HD 84948, we estimate from the mass ratio an age of about 1 Gyr, ruling out a possible Pre-Main-Sequence status. HD 171948 has an age of about 0.01 to 0.1 Gyr which is close to the Zero-Age Main Sequence. We therefore conclude that the LB phenomenon can be found continuously from very early stages to the Terminal-Age Main Sequence. These results together with those found in the literature are discussed in the light of the proposed theories explaining this phenomenon. The most acknowledged models include diffusion as main mechanism together either with mass-loss or with accretion of circumstellar material.
AB - We present high-resolution spectroscopic observations of the four LB type spectroscopic binary systems HD 64491, HD 84948, HD 141851 and HD 171948. This group of objects comprise of nonmagnetic, metal-weak, Population I, late B- to early F-type stars. For HD 64491 and HD 141851, estimates of the orbital period were derived. Whereas for the other two systems, detailed abundances and orbital elements are presented. The Hipparcos data reveal that the Galactic space motions of both systems are typical of those of Population I objects. The photometric data from the Hipparcos mission confirm the pulsation previously discovered for HD 84948 with a period of about 110 minutes and a V-amplitude of about 14 mmag. For HD 84948, we estimate from the mass ratio an age of about 1 Gyr, ruling out a possible Pre-Main-Sequence status. HD 171948 has an age of about 0.01 to 0.1 Gyr which is close to the Zero-Age Main Sequence. We therefore conclude that the LB phenomenon can be found continuously from very early stages to the Terminal-Age Main Sequence. These results together with those found in the literature are discussed in the light of the proposed theories explaining this phenomenon. The most acknowledged models include diffusion as main mechanism together either with mass-loss or with accretion of circumstellar material.
UR - http://adsabs.harvard.edu/full/2005ASPC..333..259P
M3 - Contribution to proceedings
SN - 1-58381-196-6
T3 - Astronomical Society of the Pacific Conference Series
SP - 259
BT - Tidal evolution and oscillations in binary stars
A2 - Claret, Antonio
PB - Astronomical Society of the Pacific
CY - San Francisco
ER -