1064 Aethusa

1064 Aethusa, provisional designation, is a stony background asteroid from the central regions of the asteroid belt, approximately 19 kilometers in diameter. It was discovered on 2 August 1926, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany. The asteroid was named after the plant Aethusa cynapium (fool's parsley).

Orbit and classification
Aethusa is a background asteroid with no associated asteroid family. It orbits the Sun in the central main belt at a distance of 2.1–3.0 AU once every 4 years and 1 month (1,481 days). Its orbit has an eccentricity of 0.18 and an inclination of 10° with respect to the ecliptic. The observation arc begins at Heidelberg/Simeiz Observatory two nights after the asteroid's official discovery observation.

Physical characteristics
Aethusa is an assumed stony S-type asteroid, the most common type in the inner part of the central asteroid belt.

Rotation period
In November 2004, a rotational lightcurve of Aethusa was obtained from photometric observations by French amateur astronomer René Roy at Blauvac Observatory (627). Lightcurve analysis gave a rotation period of 12.916 hours with a brightness variation of 0.12 magnitude (U=2), while in March 2006, astronomer Brian Warner at his Palmer Divide observatory in Colorado, United States, obtained a shorter period of 8.621 hours and an amplitude of 0.18 magnitude (U=2).

Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, the MIPS photometer on the Spitzer Space Telescope, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Aethusa measures between 17.42 and 25.361 kilometers in diameter and its surface has an albedo between 0.160 and 0.3202.

The Collaborative Asteroid Lightcurve Link derives a high albedo of 0.2952 and a diameter of 18.56 kilometers based on an absolute magnitude of 10.6.

Naming
This minor planet was named after the genus "Aethusa" in the carrot family, of which the plant Aethusa cynapium – commonly known as fool's parsley, fool's cicely, or poison parsley – is the only member. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 101).