The Curse of Sisyphus

Analysis of CCD photometry observations in mid-2011 of the suspected binary asteroid 1866 Sisyphus made at Lowell Observatory, Goat Mountain Astronomical Research Station (GMARS), and Palmer Divide Observatory (PDO) found two low amplitude periods of 2.40 h and 25.25 h. The shorter period is similar to that previously reported. The longer period may be due to the suspected satellite but, given the lack of mutual events (occultations and/or eclipses), the evidence is not conclusive.