801 Helwerthia is a C-type asteroid orbiting in the Main belt near the Eunomia family. However, it is not a family member but an un-related interloper in the region because its composition is inconsistent with membership. Its diameter is about 33 km, its albedo around 0.038. An international team of astronomers observed this minor planet photometrically in 2012, determining a rotation period of with an amplitude of in magnitude. References External links 000801 Discoveries by Max Wolf Named minor planets 000801 19150320