Long Baseline Interferometric Observations of Cepheids
نویسنده
چکیده
We present observations of the galactic cepheids η Aql and ζ Gem. Our observations are able to resolve the diameter changes associated with pulsation. This allows us to determine the distance to the Cepheids independent of photometric observations. We determine a distance to η Aql of 320 ± 32 pc, and a distance to ζ Gem of 362±38 pc. These observations allow us to calibrate surface brightness relations for use in extra-galactic distance determination. They also provide a measurement of the mean diameter of these Cepheids, which is useful in constructing structural models of this class of star. Subject headings: Cepheids– stars:fundamental parameters–stars:individual (η Aquilae, ζ Geminorum)
منابع مشابه
2 Long Baseline Interferometric Observations of Cepheids
We present observations of the galactic cepheids η Aql and ζ Gem. Our observations are able to resolve the diameter changes associated with pulsation. This allows us to determine the distance to the Cepheids independent of photometric observations. We determine a distance to η Aql of 320 ± 32 pc, and a distance to ζ Gem of 362±38 pc. These observations allow us to calibrate surface brightness r...
متن کاملMultiplicity of Galactic Cepheids from long-baseline interferometry
Context. More than 60% of Cepheids are in binary or multiple systems. Studying such systems could lead to a better understanding of the age and evolution of Cepheids. These are also useful tools to estimate the mass of Cepheids, and constrain theoretical models of their pulsation and evolution. Aims. We aim at determining the masses of Cepheids in binary systems, as well as their geometric dist...
متن کاملCepheid observations by long-baseline interferometry with FLUOR/IOTA
We report interferometric observations of the classical galactic Cepheid ζ Gem with FLUOR (Fiber Linked Unit for Optical Recombination), installed at the IOTA (Infrared Optical Telescope Array) interferometer. Thanks to the high precision of the visibility measurements with FLUOR, it has been possible to estimate its mean uniform disk angular diameter to a relative precision of 5 % (θud = 1.98 ...
متن کاملMean Angular Diameters and Angular Diameter Amplitudes of Bright Cepheids
We predict mean angular diameters and amplitudes of angular diameter variations for all monoperiodic Population I Cepheids brighter than 〈V 〉 = 8.0 mag. The catalog is intended to aid selecting most promising Cepheid targets for future interferometric observations.
متن کاملCepheid distances from infrared long-baseline interferometry
Using our interferometric angular diameter measurements of seven classical Cepheids reported in Kervella et al. (2003, Paper I), complemented by previously existing measurements, we derive new calibrations of the Cepheids Period–Radius (P–R) and Period–Luminosity (P–L) relations. We obtain a P–R relation of logR = [0.767 ± 0.009] logP + [1.091 ± 0.011], only 1σ away from the relation obtained b...
متن کامل