The Pleiades is the best-studied open cluster in the sky. It is one of the primary open clusters used to define the ‘zero-age main sequence,' and hence it serves as a cornerstone for programs which use main-sequence fitting to derive distances. This role is called into question by the ‘Pleiades distance controversy:' the distance to the Pleiades from Hipparcos of approximately 120 pc is significantly different from the distance of 133 pc derived using other techniques. To resolve this issue, we plan to use Very Long Baseline Interferometry to derive a new, independent trigonometric parallax distance to the Pleiades. In these proceedings we present our observational program and report some preliminary results.

We present a new determination of the distance to the Pleiades using the moving-cluster method, allowing for inclusion of the effects of expansion and rotation of the cluster. While rotation appears neglegible, we find a slight expansion of the cluster with a maximum velocity of 0.15 km s−1 and a distance modulus of (m − M)0 = 5.50 ± 0.13 mag. This is larger but compatible with the new Hipparcos distance modulus of 5.40 ± 0.03 mag. On the other hand, various distance moduli for the Pleiades are found in the literature, many resulting from isochrone fitting. They scatter around a value of 5.63 mag. Our results are also compatible with these measurements, within the error bars.