value quality siderealorsynodic author ref method 8.1917 2 Sidereal Durech 2020A&A...643A..59D Model 8.1917 2 Sidereal Durech 2023A&A...675A..24D Model 8.8650 3- Synodic Carbognani 2011MPBu...38...57C Lightcurve