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A new bright Cephei star: line-profile variability in 1 Sco *
John H. Telting 1 and
Coen Schrijvers 2
Received 5 March 1998 / Accepted 17 July 1998
We present a time series of high-resolution spectra, showing the line-profile variations in the SiIII triplet ( 4552, 4567, 4574 Å) of the rotating early-type star Sco. The profile variations can be explained by a non-radial pulsation mode.
We analyse the spectral time series by making Fourier transforms for each position in the line profile. Significant power is found only at a frequency of 15.0 cycles/day, suggesting that the profile variations are due to one dominant pulsation mode. From the difference in phase of the variations of the blue and the red wings of the profiles we infer that the star pulsates in a mode with pulsational degree . From comparison with model calculations we estimate the velocity amplitude of this pulsation to be 10 km/s at the stellar surface.
Key words: line: profiles stars: early-type stars: oscillations stars: rotation stars: variables: other stars: individual: !1 Sco
Online publication: September 30, 1998