value quality siderealorsynodic author ref method 7.6487 2 Sidereal Durech 2020A&A...643A..59D Model 7.6500 2 Synodic Waszczak 2015AJ....150...75W Lightcurve 7.6507 2 Sidereal Durech 2023A&A...675A..24D Model