value quality siderealorsynodic author ref method 6.9710 2 Synodic Waszczak 2015AJ....150...75W Lightcurve 6.9714 2 Sidereal Durech 2023A&A...675A..24D Model 6.9715 2 Sidereal Durech 2019A&A...631A...2D Model