value quality siderealorsynodic author ref method 5.9358 2 Sidereal Durech 2018A&A...617A..57D Model 5.9360 2 Synodic Erasmus 2020ApJS..247...13E Lightcurve 5.9500 2 Synodic Erasmus 2019ApJS..242...15E Lightcurve