value quality siderealorsynodic author ref method 8.9700 2+ Synodic Behrend LCDB Lightcurve 8.9806 2 Sidereal Hanus 2016A&A...586A.108H Model 8.9840 3 Synodic Shevchenko 1992Icar..100..295S Lightcurve 9.0000 2 Synodic Tedesco LCDB Lightcurve