value quality siderealorsynodic author ref method 15.7788 2 Sidereal Durech 2019A&A...631A...2D Model 15.7789 2 Sidereal Durech 2023A&A...675A..24D Model 15.7810 3 Synodic Marchini 2017MPBu...44..274M Lightcurve