Institution: | 1. Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, U.S.A.;2. Massachusetts Institute of Technology, Massachusetts Ave., Cambridge, MA 02139, U.S.A.;3. Mount Stromlo and Siding Spring Observatories, Private Bag, P.O. Woden, ACT 2606, U.S.A.;4. Columbia University, Dept. of Astronomy, New York, NY 10027, U.S.A. |