... accretion

Based on observations obtained at Observatoire de Haute Provence (CNRS, France), Mt Maidanak Obs. (Uzbekistan), Calar Alto Obs. (Spain), Teide Obs. (Spain), Byurakan Obs. (Armenia), Assy-Turgen Obs. (Kazakstan), ESO La Silla (Chile), Lick Obs. (NOAO, USA), Tautenburg Obs. (Germany) and Roque de los Muchachos Obs. (Spain).

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