value quality siderealorsynodic author ref method 6.0800 2 Synodic Chang 2015ApJS..219...27C Lightcurve 6.0830 2 Synodic Waszczak 2015AJ....150...75W Lightcurve 6.9670 2- Synodic Erasmus 2020ApJS..247...13E Lightcurve