Properties and nature of Be stars 30. Reliable physical properties of a semi-detached B9.5e+G8III binary BR CMi = HD 61273 compared to those of other well studied semi-detached emission-line binaries

Abstract

Reliable determination of the basic physical properties of hot emission-line binaries with Roche-lobe filling secondaries is important for developing the theory of mass exchange in binaries. It is a very hard task, however, which is complicated by the presence of circumstellar matter in these systems. So far, only a small number of systems with accurate values of component masses, radii, and other properties are known. Here, we report the first detailed study of a new representative of this class of binaries, BR CMi, based on the analysis of radial velocities and multichannel photometry from several observatories, and compare its physical properties with those for other well-studied systems. BR CMi is an ellipsoidal variable seen under an intermediate orbital inclination of ~51 degrees, and it has an orbital period of 12.919059(15) d and a circular orbit. We used the disentangled component spectra to estimate the effective temperatures 9500(200) K and 4655(50) K by comparing them with model spectra. They correspond to spectral types B9.5e and G8III. We also used the disentangled spectra of both binary components as templates for the 2-D cross-correlation to obtain accurate RVs and a reliable orbital solution. Some evidence of a secular period increase at a rate of 1.1+/-0.5 s per year was found. This, together with a very low mass ratio of 0.06 and a normal mass and radius of the mass gaining component, indicates that BR CMi is in a slow phase of the mass exchange after the mass-ratio reversal. It thus belongs to a still poorly populated subgroup of Be stars for which the origin of Balmer emission lines is safely explained as a consequence of mass transfer between the binary components.

arXiv comment17 pages, 5 figures, accepted for publication in Astronomy and Astrophysics. appears in Astronomy and Astrophysics 2014

References in corpus (23)

• Gaia Data Release 2. Summary of the contents and survey properties
• Validation of the new Hipparcos reduction
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• A Computational Guide to Physics of Eclipsing Binaries. Paper I. Demonstrations and Perspectives
• HERMES: a high-resolution fibre-fed spectrograph for the Mercator telescope
• Nominal values for selected solar and planetary quantities: IAU 2015 Resolution B3
• New Periodic Variables from the Hipparcos Epoch Photometry
• Random forest automated supervised classification of Hipparcos periodic variable stars
• The ASAS-SN Catalog of Variable Stars III: Variables in the Southern TESS Continuous Viewing Zone
• POLLUX : a database of synthetic stellar spectra
• The AMBRE project: A new synthetic grid of high-resolution FGKM stellar spectra
• FUV Detection of the Suspected Subdwarf Companion to the Be Star 59 Cygni
• The mass ratio and formation mechanisms of Herbig Ae/Be star binary systems
• Critically-rotating accretors and non-conservative evolution in Algols
• Revealing the Nature of Algol Disks through Optical and UV Spectroscopy, Synthetic Spectra, and Tomography of TT Hydrae
• CoRoT photometry and high-resolution spectroscopy of the interacting eclipsing binary AU Mon
• A cyclic bipolar wind in the interacting binary V393 Scorpii
• Modeling the Accretion Structure of AU Mon
• A multi-method approach to radial-velocity measurement for single-object spectra
• Spurious Eccentricities of Distorted Binary Components
• HD 152246 - a new high-mass triple system and its basic properties
• UX Monocerotis as a W Serpentis binary
• Binary evolution using the theory of osculating orbits: conservative Algol evolution

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