1. Bogolyubov Institute for Theoretical Physics, Ukrainian National Academy of Sciences , Metrologichna 14b, UA-03143 Kyiv, Ukraine
2. Astronomy Department, University of Virginia , P.O. Box 400325, Charlottesville, VA 22904-4325, USA
3. Institut d’Astrophysique de Paris (UMR 7095 CNRS & Sorbonne Université) 98 bis Bd Arago , F-75014 Paris, France