value quality siderealorsynodic author ref method 6.0000 2- Synodic Pilcher 1987MPBu...14...23P Lightcurve 7.9971 2 Sidereal Durech 2016A&A...587A..48D Model 7.9971 3- Synodic Pilcher 2015MPBu...42...91P Lightcurve