value quality siderealorsynodic author ref method 20.3544 2 Sidereal Durech 2018A&A...617A..57D Model 20.3545 2 Sidereal Durech 2023A&A...675A..24D Model 20.3840 2 Synodic Waszczak 2015AJ....150...75W Lightcurve