Additionally , since this AO system provides an excellent and stable correction ( angular resolution of 0.060 arcsec in K band ) , a 15-km moon at 1000 km from Hektor was found . Additionally , since this AO system provides an excellent and stable correction ( angular resolution of 0.060 arcsec in K band ) , a 15-km moonlet at 1000 km of Hektor 's primary was detected .