value quality siderealorsynodic author ref method 6.3850 2 Synodic Erasmus 2020ApJS..247...13E Lightcurve 6.3850 3 Synodic Farfan 2022MPBu...49..229F Lightcurve 6.3850 2 Sidereal Durech 2019A&A...631A...2D Model