Related papers: Cepheid distances from Interferometry
As primary anchors of the distance scale, Cepheid stars play a crucial role in our understanding of the distance scale of the Universe because of their period-luminosity relation. Determining precise and consistent parameters (radius,…
The projection factor (p-factor) is an essential component of the classical Baade-Wesselink (BW) technique, that is commonly used to determine the distances to pulsating stars. It is a multiplicative parameter used to convert radial…
Hydrodynamic computations of nonlinear Cepheid pulsation models with periods from 20 to 100 day on the evolutionary stage of core helium burning were carried out. Equations of radiation hydrodynamics and time--dependent convection were…
Observations of the southern Cepheid l Car to yield the mean angular diameter and angular pulsation amplitude have been made with the Sydney University Stellar Interferometer (SUSI) at a wavelength of 696 nm. The resulting mean…
Type II Cepheids are pulsating stars that can be used as standard candles for old stellar populations due to their characteristic Period-Luminosity and Period-Luminosity-Colour relations. They are traditionally divided in 3 sub-classes,…
Context: The prediction of stellar angular diameters from broadband photometry plays an important role for different applications. In particular, long-baseline interferometry, gravitational microlensing, extrasolar planet transits, and many…
Context: The effective temperature is a key parameter governing the properties of a star. For stellar chemistry, it has the strongest impact on the accuracy of the abundances derived. Since Cepheids are pulsating stars, determining their…
We present the first application of mid-infrared Period-Luminosity relations to the determination of a Cepheid distance beyond the Magellanic Clouds. Using archival IRAC imaging data on NGC 6822 from Spitzer we were able to measure…
We present a technique for decomposing Cepheid light curves into their fundamental constituent parts; that is, their radius and temperature variations. We demonstrate that any given pair of optical luminosity and color curves can be used to…
The projection factor (p), which converts the radial velocity to pulsational velocity, is an important parameter in the Baade-Wesselink (BW) type analysis and distance scale work. The p-factor is either adopted as a constant or linearly…
The determination of pulsation velocities from observed spectra of Cepheids is needed for the Baade-Wesselink calibration of these primary distance markers. The applicability of the Fourier-disentangling technique for the determination of…
We develop and describe a Bayesian statistical analysis to solve the surface brightness equations for Cepheid distances and stellar properties. Our analysis provides a mathematically rigorous and objective solution to the problem, including…
We are conducting a long-term photometric survey of the nearby galaxy M33 to discover Cepheids, eclipsing binaries, and long-period variables. The dataset combines previously-obtained optical images from the DIRECT project with new…
Asteroseismology has been extremely successful in determining the properties of stars in different evolutionary stages with a remarkable level of precision. However, to fully exploit its potential, robust methods for estimating stellar…
(ABRIDGED) We have applied the near-IR Barnes-Evans realization of the Baade-Wesselink method as calibrated by Fouque & Gieren (1997) to five metal-poor Cepheids with periods between 13 and 17 days in the Small Magellanic Cloud as well as…
One of the largest uncertainties for using the Baade-Wesselink method to measure Cepheid distances is the value of the projection factor (p-factor). However, p-factors measured using the IRSB technique and from hydrodynamic models disagree.…
Extragalactic Cepheids are the basic rungs of the cosmic distance scale. They are excellent standard candles, although their luminosities and corresponding distance estimates can be affected by the particular properties of the host galaxy.…
We have undertaken several projects with the purpose of determining accurate distances to nearby galaxies to calibrate the extragalactic distance scale. Specifically, I describe the DIRECT project which aims to derive the distance to M31…
We focus on empirically measure the p-factor of a homogeneous sample of 29 LMC and 10 SMC Cepheids for which an accurate average LMC/SMC distance were estimated from eclipsing binary systems. We used the SPIPS algorithm, which is an…
Optical long baseline interferometry was recently established as a technique capable of resolving stars and their circumstellar environments at the milliarcsecond (mas) resolution level. This high-resolution opens an entire new window to…