Angular Sizes and Effective Temperatures of O-type Stars from Optical Interferometry with the CHARA Array

Abstract

We present interferometric observations of six O-type stars that were made with the Precision Astronomical Visible Observations (PAVO) beam combiner at the Center for High Angular Resolution Astronomy (CHARA) Array. The observations include multiple brackets for three targets, $\lambda$~Ori~A, $\zeta$~Oph, and 10~Lac, but there are only preliminary, single observations of the other three stars, $\xi$~Per, $\alpha$~Cam, and $\zeta$~Ori~A. The stellar angular diameters range from 0.55 milliarcsec for $\zeta$~Ori~A down to 0.11 mas for 10~Lac, the smallest star yet resolved with the CHARA Array. The rotational oblateness of the rapidly rotating star $\zeta$ Oph is directly measured for the first time. We assembled ultraviolet to infrared flux measurements for these stars, and then derived angular diameters and reddening estimates using model atmospheres and an effective temperature set by published results from analysis of the line spectrum. The model-based angular diameters are in good agreement with observed angular diameters. We also present estimates for the effective temperatures of these stars derived by setting the interferometric angular size and fitting the spectrophotometry.

arXiv comment13 pages, 6 figures, Table 5 - MRT

References in corpus (42)

• Gaia Data Release 2. Summary of the contents and survey properties
• Validation of the new Hipparcos reduction
• Correcting for the Effects of Interstellar Extinction
• Accurate masses and radii of normal stars: modern results and applications
• A Hipparcos census of the nearby OB associations
• A new calibration of stellar parameters of Galactic O stars
• A Grid of NLTE Line-Blanketed Model Atmospheres of O-type Stars
• Gaia Data Release 2: using Gaia parallaxes
• A Grid of NLTE Line-Blanketed Model Atmospheres of Early B-type Stars
• Astrophysical parameters of Galactic open clusters
• The AKARI/IRC Mid-Infrared All-Sky Survey
• First Results from the CHARA Array. II. A Description of the Instrument
• Atmospheric NLTE-Models for the Spectroscopic Analysis of Blue Stars with Winds. II. Line-Blanketed Models
• The Galactic O-Star Spectroscopic Survey. I. Classification System and Bright Northern Stars in the Blue-Violet at R~2500
• UBVJHK synthetic photometry of Galactic O stars
• The IACOB project: I. Rotational velocities in Northern Galactic O and early B-type stars revisited. The impact of other sources of line-broadening
• Bright OB stars in the Galaxy - III. Constraints on the radial stratification of the clumping factor in hot star winds from a combined Halpha, IR and radio analysis
• The origin of runaway stars
• A New Stellar Atmosphere Grid and Comparisons with HST/STIS Calspec Flux Distributions
• Fundamental parameters of Galactic luminous OB stars VI. Temperatures, masses and WLR of Cyg OB2 supergiants
• L-band spectroscopy of Galactic OB-stars
• Spectral analysis of early-type stars using a genetic algorithm based fitting method
• Colder and Hotter: Interferometric imaging of β Cassiopeiae and α Leonis
• The VLT-FLAMES Tarantula Survey XVI. The optical+NIR extinction laws in 30 Doradus and the photometric determination of the effective temperatures of OB stars
• Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third Edition - Comments and Statistics
• Analysis of Galactic late-type O dwarfs: more constraints on the weak wind problem
• Pseudomagnitudes and Differential Surface Brightness: Application to the apparent diameter of stars
• The MiMeS Survey of Magnetism in Massive Stars: CNO surface abundances of Galactic O stars
• The IACOB project. V. Spectroscopic parameters of the O-type stars in the modern grid of standards for spectral classification
• A recalibration of IUE NEWSIPS low dispersion data
• Adaptive Optics Photometry and Astrometry of Binary Stars. III. A Faint Companion Search of O-Star Systems
• The weak magnetic field of the O9.7 supergiant zeta Orionis A
• Quantitative H and K band spectroscopy of Galactic OB-stars at medium resolution
• Optical-NIR dust extinction towards Galactic O stars
• Observational effects of magnetism in O stars: surface nitrogen abundances
• Building the 'JMMC Stellar Diameters Catalog' using SearchCal
• Optical Interferometry of early-type stars with PAVO@CHARA. I. Fundamental stellar properties
• Dynamical mass of the O-type supergiant in Zeta Orionis A
• The IACOB project: II. On the scatter of O-dwarf spectral type -- effective temperature calibrations
• A study of the effect of rotational mixing on massive stars evolution: surface abundances of Galactic O7-8 giant stars
• A Catalog of Calibrator Stars for Next-Generation Optical Interferometers
• Spectrophotometry of Very Bright Stars in the Southern Sky

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