1. INAF - Osservatorio Astronomico di Capodimonte,Napoli,Italy,80131
2. Politecnico di Milano,Department of Mechanical Engineering,Lecco,Italy,23900
3. Instituto Nacional de Técnica Aeroespacial (INTA),Madrid,Spain
4. INAF – Astrophysics and Space Science Observatory (OAS),Bologna,Italy,40129