value quality siderealorsynodic author ref method 6.5163 2 Sidereal Durech 2023A&A...675A..24D Model 6.5170 2+ Synodic Kalup 2021ApJS..254....7K Lightcurve 6.5200 2- Synodic Stephens 2014MPBu...41...95S Lightcurve