33 Polyhymnia's density measurement may be highly inaccurate, e.g., Wikipedia says:<p>> In 2012, a study by Benoît Carry estimated a mass of (6.20±0.74)×1018 kg for Polyhymnia based on its gravitational influence on other Solar System bodies. However, given Polyhymnia's diameter of 54 km (34 mi), this mass implies an extremely high density 75.28±9.71 g/cm3. Such a high density is unphysical, so this mass and density estimate of Polyhymnia is considered unreliable by Carry in his study. Because of Polyhymnia's small size, its gravitational influence on other bodies is extremely difficult to detect and may lead to highly inaccurate mass and density estimates. No other study has attempted to determine a mass and density for Polyhymnia since.