According to the survey carried out by NASA's
Wide-field Infrared Survey Explorer with its subsequent
NEOWISE mission,
Attica measures 23.681 kilometers in diameter and its surface has an
albedo of 0.105. Based on a generic
magnitude-to-diameter conversion, its diameter is between 13 and 32 kilometer for an
absolute magnitude of 11.4 and an assumed albedo in the range of 0.05 to 0.25. Since asteroids in the outer main-belt are typically of
carbonaceous rather than
stony composition, with averaged standard albedos of 0.057,
Atticas diameter can be estimated to measure close to 30 kilometers, as the lower a body's albedo (reflectivity), the larger its diameter at a fixed
absolute magnitude (brightness). As of 2017,
Atticas
spectral type, as well as its
rotation period and shape remain unknown. This is rather unusual, as both spectral type and rotation period have been determined for most larger and low-numbered asteroids
(also see minor-planet lists from 1 up to 2000). == Naming ==