value quality siderealorsynodic author ref method 16.9860 2 Sidereal Durech 2018A&A...617A..57D Model 16.9870 2 Synodic Waszczak 2015AJ....150...75W Lightcurve 16.9940 2 Synodic Waszczak 2015AJ....150...75W Lightcurve