1. Department of Chemistry, Wellesley College, Wellesley, Massachusetts 02481, United States
2. INAF─Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5, 50125 Firenze, Italy
3. Department of Physics & Astronomy, Benedictine College, Atchison, Kansas 66002, United States
4. Department of Physics & Astronomy, Wellesley College, Wellesley, Massachusetts 02481, United States