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An Adjustment to Cepheid Distances Calculated Using Model Atmospheres

Published online by Cambridge University Press:  15 February 2018

Robert Hindsley
Affiliation:
U.S. Naval Observatory, Washington, D.C.
R.A. Bell
Affiliation:
University of Maryland

Extract

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Hindsley and Bell (1989, Ap. J., 341, 1004) determined distances for 23 Cepheids using the surface brightness method. The color V – IC on the Cousins system or V – RJ on the Johnson system was used to measure visual surface brightness. Combined with the observed visual magnitudes, angular diameters were then calculated. Comparison of angular diameters with radius differences in linear units, obtained by integrating the radial velocity curve, yielded each Cepheid's distance.

Hindsley and Bell calibrated the relationship between color and surface brightness using model atmospheres. The zero point of the relationship was found using observations of Vega and an appropriate model. More recently the spectral scans of Gunn and Strycker (1983, Ap. J. Suppl., 52, 121) and the Cousins filter response curves of Hindsley and Bell were used to calculate colors and these were compared to the corresponding observed colors.

Type
Variable Stars as Distance Indicators
Copyright
Copyright © Cambridge University Press 1993