value quality siderealorsynodic author ref method 6.7754 2 Sidereal Durech 2023A&A...675A..24D Model 6.7755 3 Synodic Owings 2019MPBu...46..272O Lightcurve 6.7800 3 Synodic Rowe 2019MPBu...46..353R Lightcurve