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Precise Radial Velocities of F, G, K Dwarfs

Published online by Cambridge University Press:  19 July 2016

Bruce Campbell  and
Gordon A. H. Walker
Bruce Campbell
Affiliation:
Physics Department, University of Victoria, Victoria, B.C., V8W 2Y2, Canada
Gordon A. H. Walker
Affiliation:
Stephenson Yang Geophysics and Astronomy Department, University of British Columbia, Vancouver, B.C., V6T 1W5, Canada

Abstract

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We have monitored changes in the radial velocities of 24 bright F, G and K dwarf stars (known spectroscopic binaries excluded) for the past six years at CFHT by imposing the absorption lines of HF gas in the spectra to act as wavelength fiducials. The average external error in the δ(velocities) which are based on some 16 stellar lines is 13 m/s corresponds to 0.6 micron in the spectrum or 0.04 of a diode spacing per line. Reductions are complete for 16 stars. There is no evidence for brown dwarf companions in the sample. Two previously unknown spectroscopic binaries were found, and seven stars show indications of significant, long-term, low-level velocity variations which could be interpreted as purturbations by companions of a few Jupiter masses with periods greater than 12 years except for γ Cep, which may have a period of 2.7 years, and ε Eri. Observing time has been guaranteed for at least two more years at CFHT.

Type
I. Spectrographs, Detectors, Fourier Transform Spectroscopy, and Radial Velocities
Information
Symposium - International Astronomical Union , Volume 132: The Impact of Veryhigh S/N Spectroscopy on Stellar Physics , 1988 , pp. 79 - 81
Copyright
Copyright © Kluwer 1988 

References

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