1. Department of Physics, Kansas State University, 116 Cardwell Hall, Manhattan, KS 66506, USA
2. Division of Theoretical Astrophysics, National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
3. Max Planck Institute for Astrophysics, Karl-Schwarzschild Str. 1, Postfach 1317, Garching D-85741, Germany
4. European Southern Observatory, Karl-Schwarzschild Str. 2, Garching D-85748, Germany
5. Warsaw University Observatory, Aleje Ujazdowskie 4, 00-478 Warszawa, Poland