Institution: | a Astronomical Institute of Kharkov V.N. Karazin National University, 35 Sumskaya Street, Kharkov 61022, Ukraine b Army Research Laboratory, AMSRD-ARL-CI-EM, 2800 Powder Mill Road, Adelphi, MA 20783, USA c Astronomical Institute “Anton Pannekoek,” University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands |