1999/04/22 by P. Lanoix, Lanoix, P., G. Paturel +3
Earth and Planetary Sciences · Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astrophysics (astro-ph) #FOS: Physical sciences #Geophysics and Gravity Measurements #History and Developments in Astronomy #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9904298
12 pages, 13 figures, accepted to MNRAS
arxiv created 1999/04/22 · openalex publication_date 1999/04/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
After the first release of HIPPARCOS data, Feast & Catchpole gave a new value to the zero-point of the visual Cepheid Period-Luminosity relation based on trigonometric parallaxes. Because of the large uncertainties on these parallaxes, the way in which individual measurements are weighted bears a crucial importance, and the discrepancy they show leads to the conclusion that the choice of the best weighting system can be provided through a Monte-Carlo simulation. On the basis of such a simulation it is shown that: - A cut in πor in σπ / πintroduces a strong bias. - The zero-point is more stable when only the brightest Cepheids are used. - The Feast & Catchpole weighting gives the best zero-point and the lowest dispersion. After correction, the adopted visual Period-Luminosity relation is: = -2.77 log P - 1.44 ± 0.05. Moreover, we extend this study to the photometric I-band (Cousins) and obtain: = -3.05 log P - 1.81 ± 0.09.