"erna" is a non-family asteroid from the main belt's background population. it orbits the sun in the outer asteroid belt at a distance of 2.4–3.4 au once every 4 years and 12 months (1,818 days). its orbit has an eccentricity of 0.18 and an inclination of 4° with respect to the ecliptic. the body's observation arc begins at the united states naval observatory in september 1905, more than 10 years after its official discovery observation at nice.