\journalname
Astronomy&AstrophysicsReview
Additional data
\label{auxdata}
Mass and radius are the data that can be determined directly from observation without relying on external data or calibrations. However, to fully utilise the power of these parameters, additional data are needed. These are, most importantly, the effective temperature and chemical composition of the stars, followed by their rotational velocities and the amount of interstellar reddening; the latter is needed when deriving effective temperatures, luminosities, and distances. We provide these data for the systems in Table \ref{tableMR} as far as possible, and briefly describe our selection of them here.
\label{teff}Effective temperature.
Effective temperatures are usually determined from multicolour photometry via an appropriate calibration, although spectroscopic excitation temperatures are used occasionally when the two spectra can be separated. The determinations available in the literature are rather heterogeneous, being typically based on photometry in a variety of systems as selected by the original observers, and using a variety of calibrations as necessary to cover a temperature range from 3,100 K to 38,000 K.
It is an essentially impossible task to place all the temperature determinations on a consistent – let alone correct – scale; this would require obtaining new optical and IR photometry for many systems and an in-depth review of the corresponding temperature calibrations, a task well beyond the scope of this paper. Instead, we have checked the data, calibrations, and determinations of interstellar reddening, if any, in the original papers, and have searched the literature for any other reddening determinations. When known, our adopted \(E(B-V)\) value for each system is listed in Table \ref{tableMRsup} and has been used to estimate \(T_{\rm eff}\) and its uncertainty. The resulting values of \(T_{\rm eff}\) have typical errors of \(\sim\)2%, but some stars have considerably larger errors, as indicated in Table \ref{tableMR}.
From the measured radius \(R\) and the adopted value of \(T_{\rm eff}\), the luminosity \(L\) of each star is computed and listed in Table \ref{tableMR}. Adopting the scale of bolometric corrections \(BC_{V}\) by \cite{flower} and a consistent value of \(M_{\rm bol,\odot}\) (essential!), the absolute visual magnitude \(M_{V}\) follows and is reported as well; note that the \cite{flower} \(BC_{V}\) may not be accurate for the lowest-mass stars.
\label{distance}Distances.
From the apparent visual magnitudes \(V_{\rm max}\) listed in Table \ref{tableMR}, \(M_{V}\) as computed above, and the reddenings listed in Table \ref{tableMRsup}, the distance of each system follows and is also given in Table \ref{tableMRsup}. As seen, the accuracy of these distances is remarkably good, with an average error of only 5% (disregarding a few outliers). This has led to the use of extragalactic eclipsing binaries as distance indicators – including one system listed here (OGLE 051019). It must be recalled, however, that these distances are sensitive to any systematic errors in \(T_{\rm eff}\), on which they depend as \(T_{\rm eff}^{2}\).