Observations with the adaptive optics system on the Very Large Telescope reveal that outer main belt asteroid ( 702 ) Alauda has a small satellite with primary to secondary diameter ratio of \sim 56 .
The secondary revolves around the primary in 4.9143 \pm 0.007 days at a distance of 1227 \pm 24 km , yielding a total system mass of ( 6.057 \pm 0.36 ) \times 10 ^ { 18 } kg .
Combined with an IRAS size measurement , our data yield a bulk density for this B-type asteroid of 1570 \pm 500 kg m ^ { -3 } .