The study of detached eclipsing binaries is one of the most powerful ways to investigate the properties of individual stars and stellar systems .
We present preliminary masses , radii and effective temperatures for the eclipsing binary WW Aurigae , which is composed of two metallic-lined A-type stars .
We also reanalyse the data on HD 23642 , an A-type eclipsing binary member of the Pleiades open cluster with a metallic-lined component , and determine its distance to be 139 \pm 4 pc .
This is in agreement with the traditional Pleiades distance , but in disagreement with distance to the Pleiades , and to HD 23642 itself , derived from Hipparcos trigonometrical parallaxes .