Photometric Solutions for Detached Eclipsing Binaries: selection of ideal distance indicators in the SMC
نویسندگان
چکیده
Detached eclipsing binary stars provide a robust one-step distance determination to nearby galaxies. As a by-product of Galactic microlensing searches, catalogs of thousands of variable stars including eclipsing binaries have been produced by the OGLE, MACHO and EROS collaborations. We present photometric solutions for detached eclipsing binaries in the Small Magellanic Cloud (SMC) discovered by the OGLE collaboration. The solutions were obtained with an automated version of the Wilson-Devinney program. By fitting mock catalogs of eclipsing binaries we find that the normalized stellar radii (particularly their sum) and the surface brightness ratio are accurately described by the fitted parameters and estimated standard errors, despite various systematic uncertainties. In many cases these parameters are well constrained. In addition we find that systems exhibiting complete eclipses can be reliably identified where the fractional standard errors in the radii are small. We present two quantitatively selected sub-samples of eclipsing binaries that will be excellent distance indicators. These can be used both for computation of the distance to the SMC and to probe its structure. One particularly interesting binary has a very well determined solution, exhibits complete eclipses, and is comprised of well detached G-type, class II giants. Subject headings: stars: eclipsing binaries distance scale
منابع مشابه
Photometric Solutions for Semi-Detached Eclipsing Binaries: Selection of Distance Indicators in the Small Magellanic Cloud
Estimation of distances to nearby galaxies by the use of eclipsing binaries as standard candles has recently become feasible because of new large scale instruments and the discovery of thousands of eclipsing binaries as spinoff from Galactic microlensing surveys. Published measurements of distances to detached eclipsing binaries in the Large Magellanic Cloud combine stellar surface areas (in ab...
متن کاملLight curve solutions for bright detached eclipsing binaries in SMC: absolute dimensions and distance indicators
This paper presents a careful and detailed light curve analysis of bright detached eclipsing binaries (DEB) in the Small Magellanic Cloud, discovered by OGLE collaboration, on the basis of recently available difference image analysis (DIA) photometry. The 19 binaries brighter than 16.4 mag in I band and with the depth of primary and secondary eclipse greater than 0.25 mag were investigated. The...
متن کاملEclipsing binaries in the Magellanic Clouds . ⋆ uvby CCD light curves and photometric analyses for HV 982 ( LMC ) , HV 12578 ( LMC ) , HV 1433 ( SMC ) , and HV 11284 ( SMC )
Eclipsing binaries in the Magellanic Clouds. ⋆ uvby CCD light curves and photometric analyses for Abstract. We present new accurate CCD uvby light curves for the LMC eclipsing binaries HV982 and HV12578, and for the SMC systems HV1433 and HV11284 obtained at the Danish 1.5m telescope at ESO, La Silla. The light curves were derived from DoPHOT photometry, and typical accuracies are between 0.007...
متن کاملEclipsing Binaries: Tools for Calibrating the Extragalactic Distance Scale
In the last decade, over 7000 eclipsing binaries have been discovered in the Local Group through various variability surveys. Measuring fundamental parameters of these eclipsing binaries has become feasible with 8 meter class telescopes, making it possible to use eclipsing binaries as distance indicators. Distances with eclipsing binaries provide an independent method for calibrating the extrag...
متن کاملThe Contribution of Microlensing Surveys to the Distance Scale
In the early nineties several teams started large scale systematic surveys of the Magellanic Clouds and the Galactic Bulge to search for microlensing effects. As a by product, these groups have created enormous time-series databases of photometric measurements of stars with a temporal sampling duration and accuracy which are unprecedented. They provide the opportunity to test the accuracy of pr...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2001