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arXiv · 2505.13627

Mass of Cepheid V350 Sgr Incorporating Interferometry and the Companion Mass

Nancy Remage Evans·Alexandre Gallenne·Pierre Kervella·H. Moritz Guenther·Joanna Kuraszkiewicz·Richard I. Anderson·Charles Proffitt·Antoine Merand·Boris Trahin·Giordano Viviani·Shreeya Shetye
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Abstract

The system V350 Sgr has a classical Cepheid for the primary. Interferometry is presented for the system and the full orbit is determined. The mass of the companion has been determined from an {\it IUE} spectrum and comparison with the mass-temperature relation from Detached Eclipsing Binaries. Combined with the mass of the companion (2.6 $\pm$ 0.2 M$_\odot$), the mass of the Cepheid is determined to be 4.7 $\pm$ 0.8 M$_\odot$. For systems with less complete information, Cepheid masses can be determined from a single-lined spectroscopic orbit, {\it Gaia} proper motion anomalies, and the mass of the companion from the ultraviolet. Uncertainties resulting from different approaches to mass determination are discussed, and are expected to be reduced after the {\it Gaia} DR4 release. Temperatures for Morgan Keenan (MK) standard stars from the ultraviolet are also provided.

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Nancy Remage Evans, Alexandre Gallenne, Pierre Kervella, H. Moritz Guenther, Joanna Kuraszkiewicz, Richard I. Anderson, Charles Proffitt, Antoine Merand, Boris Trahin, Giordano Viviani, Shreeya Shetye. 2025-05-19. Mass of Cepheid V350 Sgr Incorporating Interferometry and the Companion Mass. https://arxiv.org/abs/2505.13627

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