AbstractNew radial velocities by Butler are used to recalculate the absolute magnitudes of Eta Aquilae and X Cygni using the Barnes-Evans method. The new velocities have little effect on the result for Eta Aquilae, but the absolute magnitude of X Cygni is found to be 0.40 mag fainter than that obtained earlier.

The visual surface brightness of K/M giants and dwarfs with near-solar metallicity differ slightly in agreement with the gravity effects predicted by recent theoretical models. We show that M-dwarfs display also a metallicity dependence of the surface brightness in the infrared $K$-band in agreement with theory. Based on these results, we present improved Barnes-Evans type relations and estimate the radii of 60 single or presumed M and K-dwarfs

AbstractThe relation of the surface brightness, a parameter related to the apparent magnitude and the angular diameter of a star, with a colour index is used to determine various stellar parameters. Eclipsing spectroscopic binaries can even be used as a distance indicator. In this work, we use a number of low-mass eclipsing binaries, whose parameters have been accurately determined, to refine the Barnes-Evans–like relation FV − (Ic − K) introduced by Amado et al. (1999), a relation more suitable for the low temperature of these cool stars.

view Abstract Citations (179) References (55) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Radii of nearby stars: an application of the Barnes-Evans relation. Lacy, C. H. Abstract A method of estimating radii of all nearby stars is presented. The method is based on the Barnes-Evans Fv(V R) relation and is free of assumptions about spectral classification, luminosity class, effective temperature, or bolometric correction. The method is applied to all nearby stars with accurate parallaxes and V - R photometry, and the resulting radii are compared to theoretical models. It is found that theory and observation are in good agreement for stars of about one solar mass or greater, but theoretical models of M dwarfs have up to 25% smaller radii than real stars. This conclusion is supported by the results of three other independent studies. We speculate that the cause of the discrepancy is an inadequate treatment of the opacity sources in the atmospheres and envelopes in current stellar evolution codes. Subject headings: stars: atmospheres - stars: luminosities Publication: The Astrophysical Journal Supplement Series Pub Date: August 1977 DOI: 10.1086/190459 Bibcode: 1977ApJS...34..479L full text sources ADS | data products SIMBAD (237) Related Materials (1) Addendum: 1978ApJS...36..621L

Context. Barnes-Evans type relations provide an empirical relationship between the surface brightness of stars and their color. They are widely used for measuring the distances to stars of known radii, as the Roche-lobe filling secondaries in cataclysmic variables (CVs).

view Abstract Citations (55) References (26) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Near-Infrared Variants of the Barnes-Evans Method for Finding Cepheid Distances Calibrated With High-Precision Angular Diameters Welch, Douglas L. Abstract The advantages of a near-infrared variant of the Barnes-Evans method for estimating distances to Cepheid variables are described and quantified. A surface brightness-color relation for $K$ photometry and the $(V-K)_0$ color index is established using modern, high-precision angular diameters from optical interferometers. Applied to data for the galactic (cluster) Cepheid U Sgr, this method yields a distance of 0.660 $\pm$ 0.024 kpc and a true distance modulus of 9.10 $\pm$ 0.07 mag. This estimate compares with the true distance modulus of 9.37 $\pm$ 0.22 mag estimated by Gieren, Barnes, and Moffett (1993) using the classical Barnes-Evans technique. The possibility of estimating distances of LMC and SMC Cepheids directly -- without intermediate steps -- is discussed. The feasibility of determining the distance of M31 or M33 using this technique is examined and is probably within the reach of 8m-class telescopes. Publication: The Astronomical Journal Pub Date: October 1994 DOI: 10.1086/117164 arXiv: arXiv:astro-ph/9407088 Bibcode: 1994AJ....108.1421W Keywords: Astrometry; Astronomical Interferometry; Astronomical Photometry; Brightness; Calibrating; Cepheid Variables; Diameters; Distance; Infrared Astronomy; Magellanic Clouds; Near Infrared Radiation; Absorption Spectra; Infrared Photometry; Stellar Color; Astronomy; STARS: DISTANCES; CEPHEIDS; STARS: FUNDAMENTAL PARAMETERS; Astrophysics E-Print: 19 pages + 3 figures, uuencoded compressed postscript, DLW-94-1 full text sources arXiv | ADS | data products SIMBAD (15)

The advantages of a near-infrared variant of the Barnes-Evans method for estimating distances to Cepheid variables are described and quantified. A surface brightness-color relation for $K$ photometry and the $(V-K)_0$ color index is established using modern, high-precision angular diameters from optical interferometers. Applied to data for the galactic (cluster) Cepheid U Sgr, this method yields a distance of 0.660 $\pm$ 0.024 kpc and a true distance modulus of 9.10 $\pm$ 0.07 mag. This estimate compares with the true distance modulus of 9.37 $\pm$ 0.22 mag estimated by Gieren, Barnes, and Moffett (1993) using the classical Barnes-Evans technique. The possibility of estimating distances of LMC and SMC Cepheids directly -- without intermediate steps -- is discussed. The feasibility of determining the distance of M31 or M33 using this technique is examined and is probably within the reach of 8m-class telescopes.

Direct diameter observations of Cepheid variables are used to calibrate the Barnes-Evans Cepheid surface brightness relation. Fifty-nine separate Cepheid diameter measurements from four different optical interferometers are used to calculate surface brightnesses as a function of magnitude and color. The linear fit to Cepheid surface brightness versus color is in excellent agreement with functions in the literature found using interferometric observations of non-variable giant and supergiant stars (Fouque & Gieren 1997). Using these relations the distance is calculated to delta Cephei, for which an independent distance is known from trigonometric parallax. The distance from the relation in this paper differs from that derived by the previously published relation by 4% but is still marginally within the combined errors. Both distances are well within the errors of the distance derived from trigonometric parallax.

Direct diameter observations of Cepheid variables are used to calibrate the Barnes-Evans Cepheid surface brightness relation. Fifty-nine separate Cepheid diameter measurements from four different optical interferometers are used to calculate surface brightnesses as a function of magnitude and color. The linear fit to Cepheid surface brightness versus color is in excellent agreement with functions in the literature found using interferometric observations of non-variable giant and supergiant stars (Fouque & Gieren 1997). Using these relations the distance is calculated to delta Cephei, for which an independent distance is known from trigonometric parallax. The distance from the relation in this paper differs from that derived by the previously published relation by 4% but is still marginally within the combined errors. Both distances are well within the errors of the distance derived from trigonometric parallax.

Richard J. Evans, editor. Society and Politics in Wilhelmine Germany. New York: Barnes and Noble. 1978. Pp. 305. $19.50 Evans Richard J., editor. Society and Politics in Wilhelmine Germany. New York: Barnes and Noble. 1978. Pp. 305. $19.50. Beverly Heckart Beverly Heckart Central Washington University Search for other works by this author on: Oxford Academic Google Scholar The American Historical Review, Volume 84, Issue 2, April 1979, Page 480, https://doi.org/10.1086/ahr/84.2.480 Published: 01 April 1979