1. Institut UTINAM, UMR 6213 / CNRS / Univ. Bourgogne Franche-Comté, OSU THETA, BP 1615, 25010 Besançon Cedex, France
2. Astronomical Observatory Institute, Faculty of Physics, Adam Mickiewicz University, ul. Sloneczna 36, 60-286 Poznan, Poland
3. Main Astronomical Observatory of NAS of Ukraine, 27 Akademika Zabolotnoho Street, 03680 Kyiv, Ukraine
4. LGL-TPE, UMR 5276 / CNRS, Univ. de Lyon, Univ. Claude Bernard Lyon 1, ENS Lyon, 69622 Villeurbanne Cedex, France