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T. S. Josephs, D. R. Gies, W. G. Bagnuolo, Jr. (GSU), Z. Wang (MIT), L. Penny (College of Charleston)
HD 163181 (V453 Sco) is a massive system consisting of a B-supergiant and a companion which is difficult to detect spectroscopically. The system appears to be undergoing mass transfer or loss. We present new orbital elements based on high dispersion IUE cross-correlation measurements combined with radial velocities from blue spectra obtained with the Mount Stromlo 74-inch telescope. We derive a period of P = 12.00584 ±0.00010 days. The other orbital elements agree with previous studies, except we find a larger longitude of periastron (amounting to a change of 0.9 degrees per year based on a comparison with Sahade & Frieboes-Conde 1964). This advance could be interpreted as apsidial motion, but caution is required since the eccentricity may be spurious due to emission filling from circumstellar gas. There is some evidence of a secondary spectrum in the IUE CCFs during the phase of secondary approach, but not at other phases (perhaps an extreme example of the Struve-Sahade effect).
The author(s) of this abstract have provided an email address for comments about the abstract: tammy@chara.gsu.edu