The Cepheid P–L Relation and Metallicity
نویسندگان
چکیده
منابع مشابه
The metallicity dependence of the Cepheid PL-relation
A sample of 37 Galactic, 10 LMC and 6 SMC cepheids is compiled for which individual metallicity estimates exist and BV IK photometry in almost all cases. The Galactic cepheids all have an individual distance estimate available. For the MC objects different sources of photometry are combined to obtain improved periods and mean magnitudes. A multiparameter Period-Luminosity relation is fitted to ...
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With the aid of stellar atmosphere models, we derive iron abundances [Fe/H] from the OGLE B, V , I photometry on the Magellanic Cloud Cepheids. We show that in both clouds the average metallicities of the first overtone variables are lower than those of the fundamental ones (by ∼ 0.2 and ∼ 0.3 dex in the LMC and SMC, respectively). Consequently, there is a correlation between the overall [Fe/H]...
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This study combines data from a set of seven Cepheid-calibrated galaxies in Virgo, Leo I and Fornax and four supernovæ with known metallicities, including metallicity corrections to the Cepheid distances, in order to determine a consistent mean value for the Hubble constant. We derive Virgo and Coma distances over different paths, starting from the metallicity corrected Cepheid distances of Vir...
متن کاملA study using galaxies with distances from the Cepheid PL-relation
Cepheid distances of local galaxies (< 7 Mpc) are used to study the very nearby velocity field, as pioneered by Sandage (1986) who also pointed out its remarkable properties: linearity and quietness. The new data show that the velocity dispersion in the distance range as seen from the barycentre of the Local Group 1 − 8 Mpc is as low as 38 km s. The local rate of expansion coincides with the gl...
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Hipparcos trigonometrical parallaxes of Cepheid variables are used to derive a zero-point for the PL relation. Adopting a slope from the LMC, the relation is found to be, The standard error of the zero-point is 0.10 mag. Together with metallicity corrections this corresponds to distance moduli of 18:70 0:10 for the LMC and 24:77 0:11 for M31. Some implications of these results are discussed. Es...
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ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 2000
ISSN: 0252-9211
DOI: 10.1017/s0252921100057535