FN CMa is visually double with a separation of about 0.6arcsec. Sixty high-cadence VLT/UVES spectra permit the A and B components to be disentangled, as the relative contribution of each star to the total light entering the spectrograph fluctuates between exposures due to changes in seeing. Component A exhibits rapid line-profile variations, leading us to attribute the photometric variability seen by HIPPARCOS (with a derived P=0.08866d) to this component. From a total of 122 archival and new echelle spectra it is shown that component A is an SB1 binary with an orbital period of 117.55 days. The eccentricity of 0.6 may result in tidal modulation of the pulsation(s) of component Aa.
@article{arxiv.1009.3512,
title = {The (B0+?)+O6 system FN CMa: A case for tidal-pulsational interaction?},
author = {Th. Rivinius and O. Stahl and S. Štefl and D. Baade and R. H. D. Townsend and L. Barrera},
journal= {arXiv preprint arXiv:1009.3512},
year = {2015}
}
Comments
2 pages, 1 figure, IAUS 272 - Active OB Stars: Structure, Evolution, Mass Loss and Critical Limits