Kambe, E. ; Hirata, R. ; Kato, M. ; Ando, H. ; Cuypers, J. ; Kennelly, E. J. ; Walker, G. A. H. ; Stefl, S. ; Tarasov, A. E.

published in Bulletin of the American Astronomical Society, 28, pp. 59.10 (1996)

Abstract: From simultaneous multi-site high-resolution spectroscopic and photometric observations of zeta Ophiuchi in 1993, we find that the line-profile variations of HeI lambda 6678 are well reproduced by two large and some small amplitude sinusoids. The periods of the two principal sinusoids, 2.018 hr and 3.337 hr are commensurate with a superperiod of 10.05 hr. Although our data in the period is limited, our photometric observations confirmed again very small amplitude of the light variations, close to their detection limit. No counterpart of the 2.018 hr and 3.337 hr periods can be reliably detected.

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