Angular Diameters of Stars from the Mark III Optical Interferometer

Observations of 85 stars were obtained at wavelengths between 451 and 800 nm with the Mark III Stellar Interferometer on Mount Wilson, near Pasadena, California. Angular diameters were determined by fitting a uniform-disk model to the visibility amplitude versus projected baseline length. Half the angular diameters determined at 800 nm have formal errors smaller than 1%. Limb-darkened angular diameters, effective temperatures, and surface brightnesses were determined for these stars, and relationships between these parameters are presented. Scatter in these relationships is larger than would be expected from the measurement uncertainties. We argue that this scatter is not due to an underestimate of the angular diameter errors; whether it is due to photometric errors or is intrinsic to the relationship is unresolved. The agreement with other observations of the same stars at the same wavelengths is good; the width of the difference distribution is comparable to that estimated from the error bars, but the wings of the distribution are larger than Gaussian. Comparison with infrared measurements is more problematic; in disagreement with models, cooler stars appear systematically smaller in the near-infrared than expected, warmer stars larger.

[1]  R. H. Brown,et al.  The Angular Diameters of 32 Stars , 1974 .

[2]  J. Mathis,et al.  The relationship between infrared, optical, and ultraviolet extinction , 1989 .

[3]  V. Straižys.  Multicolor Stellar Photometry , 1992 .

[4]  Braden E. Hines,et al.  Stellar Diameter Measurements with the Mark III Interferometer , 1988 .

[5]  David Mozurkewich,et al.  Angular diameter measurements of stars , 1991 .

[6]  Angular diameters by the lunar occultation techniques. VI - Limb darkening of alpha Tauri , 1982 .

[7]  Carlos Jaschek,et al.  The Bright Star Catalogue , 1982 .

[8]  R. Hindsley,et al.  The period-luminosity relation for cepheid variable stars , 1989 .

[9]  H. M. Dyck,et al.  Radii and Effective Temperatures for G, K, and M Giants and Supergiants , 1996 .

[10]  Richard O. Gray,et al.  The Physical Basis of Luminosity Classification in the Late A-, F-, and Early G-Type Stars. I. Precise Spectral Types for 372 Stars , 2001 .

[11]  David Mozurkewich,et al.  Comparison of Stellar Angular Diameters from the NPOI, the Mark III Optical Interferometer, and the Infrared Flux Method , 2001 .

[12]  Roger A. Bell,et al.  The effective temperatures and colours of G and K stars , 1989 .

[13]  D. Mozurkewich,et al.  Angular Diameter Measurements of 24 Giant and Supergiant Stars from the Mark III Optical Interferometer , 1989 .

[14]  A. V. Holm,et al.  Ultraviolet photometry from the Orbiting Astronomical Observatory. XXXIV - Filter photometry of 531 stars of diverse types , 1980 .

[15]  D. W. Latham,et al.  A rediscussion of the atmospheric extinction and the absolute spectral-energy distribution of Vega. , 1975 .

[16]  D. Welty,et al.  A High-Resolution Survey of Interstellar K I Absorption , 1996 .

[17]  Michael J. Barlow,et al.  Spectral irradiance calibration in the infrared. I - Ground-based and IRAS broadband calibrations , 1992 .

[18]  Predicting Stellar Angular Sizes , 1999, astro-ph/9904295.

[19]  David Mozurkewich,et al.  Angular diameter measurements of cool giant stars in strong TiO bands and in the continuum , 1993 .

[20]  Tyler E. Nordgren,et al.  Stellar Angular Diameters of Late-Type Giants and Supergiants Measured with the Navy Prototype Optical Interferometer , 1999 .

[21]  M. J. Shallis,et al.  Stellar angular diameters from infrared photometry. Application to Arcturus and other stars; with effective temperatures. , 1977 .

[22]  D. Ciardi,et al.  Altair’s Oblateness and Rotation Velocity from Long-Baseline Interferometry , 2001 .

[23]  Thomas G. Barnes,et al.  Stellar Angular Diameters and Visual Surface Brightness — I LATE SPECTRAL TYPES , 1976 .