The Magnetic Early B-type Stars II: stellar atmospheric parameters in the era of Gaia

Abstract

Atmospheric parameters determined via spectral modelling are unavailable for many of the known magnetic early B-type stars. We utilized high-resolution spectra together with NLTE models to measure effective temperatures $T_{\mathrm{eff}}$ and surface gravities $\log g$ of stars for which these measurements are not yet available. We find good agreement between our $T_{\mathrm{eff}}$ measurements and previous results obtained both photometrically and spectroscopically. For $\log g$, our results are compatible with previous spectroscopic measurements; however, surface gravities of stars previously determined photometrically have been substantially revised. We furthermore find that $\log g$ measurements obtained with HARPSpol are typically about 0.1 dex lower than those from comparable instruments. Luminosities were determined using Gaia Data Release 2 parallaxes. We find Gaia parallaxes to be unreliable for bright stars ($V<6$ mag) and for binaries; in these cases we reverted to Hipparcos parallaxes. In general we find luminosities systematically lower than those previously reported. Comparison of $\log g$ and $\log L$ to available rotational and magnetic measurements shows no correlation between either parameter with magnetic data, but a clear slow-down in rotation with both decreasing $\log g$ and increasing $\log L$, a result compatible with the expectation that magnetic braking should lead to rapid magnetic spindown that accelerates with increasing mass-loss.

21 pages, 3 tables, 15 figures, accepted for publication in MNRAS

References in corpus (24)

• A Grid of NLTE Line-Blanketed Model Atmospheres of Early B-type Stars
• Dynamical Simulations of Magnetically Channeled Line-Driven Stellar Winds: III. Angular Momentum Loss and Rotational Spindown
• The MiMeS survey of magnetism in massive stars: Magnetic analysis of the O-type stars
• Evolutionary state of magnetic chemically peculiar stars
• Gravito-inertial and pressure modes detected in the B3 IV CoRoT target HD 43317
• Chemically peculiar stars and their temperature calibration
• The Magnetic Early B-type Stars I: Magnetometry and Rotation
• Fundamental properties of nearby single early B-type stars
• Discovery of two magnetic massive stars in the Orion Nebula Cluster: a clue to the origin of neutron star magnetic fields?
• B fields in OB stars (BOB): Concluding the FORS2 observing campaign
• Discovery of new magnetic early-B stars within the MiMeS HARPSpol survey
• The surface magnetic field and chemical abundance distributions of the B2V helium-strong star HD184927
• HD 156324: a tidally locked magnetic triple spectroscopic binary with a disrupted magnetosphere
• Fundamental Parameters of He-Weak and He-Strong Stars
• The magnetic field and spectral variability of the He-weak star HR 2949
• High-precision elements of double-lined spectroscopic binaries from combined interferometry and spectroscopy. Application to the beta Cephei star beta Centauri
• B field in OB stars (BOB): The outstandingly strong magnetic field in the evolved He-strong star CPD-62 2124
• B fields in OB stars (BOB): FORS2 spectropolarimetric follow-up of the two rare rigidly rotating magnetosphere stars HD23478 and HD345439
• The pulsating magnetosphere of the extremely slowly rotating magnetic $\beta$ Cep star ${\xi }^1$ CMa
• Magnetic characterization of the SPB/$\beta$ Cep hybrid pulsator HD 43317
• The Lorentz force in atmospheres of CP stars: $\theta$ Aurigae
• HD 164492C: a rapidly-rotating, H$\alpha$-bright, magnetic early B star associated with a 12.5d spectroscopic binary
• The origin of magnetic fields in hot stars
• Magnetic field geometry and chemical abundance distribution of the He-strong star CPD -57 3509

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• MOBSTER -- VII. Using light curves to infer magnetic and rotational properties of stars with centrifugal magnetospheres
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