The Cepheid period–luminosity zero-point from radial velocities and Hipparcos proper motions |
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| Authors: | Michael Feast,Frederic Pont,& Patricia Whitelock |
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| Affiliation: | Astronomy Department, University of Cape Town, Rondebosch, 7700, South Africa,;Geneva Observatory, CH-1290 Sauverny, Switzerland,;South African Astronomical Observatory, PO Box 9, Observatory, 7935, South Africa |
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| Abstract: | A value for the zero-point (ρ) of the Cepheid period–luminosity relation, < M V >= 2.81 log P + ρ, is deduced by comparing the value of the Oort constant, A , derived from radial velocities with that derived from Hipparcos proper motions. We find in this way that ρ =−1.47 ± 0.13, in excellent agreement with the value derived from Hipparcos trigonometrical parallaxes, ρ = −1.43 ± 0.10, by Feast &38; Catchpole in a recent paper. |
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| Keywords: | Cepheids Galaxy: fundamental parameters distance scale |
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