In the
Tholen classification,
Inkeris
spectral type is ambiguous (XFU). It is closest to that of an
X-type asteroid and somewhat similar to the
F-types. In addition, the spectrum has also been flagged as "unusual" (U).
Slow rotator and tumbler In December 2011, a rotational
lightcurve of
Inkeri was obtained from photometric observations by Andrea Ferrero at the Bigmuskie Observatory , Italy, in collaboration with
Frederick Pilcher at the Organ Mesa Observatory in New Mexico, United States. Analysis of the bimodal lightcurve gave an exceptionally long
rotation period of 660 hours with a brightness amplitude of 1.30
magnitude (). This makes it one of the
slowest rotators known to exist. The observers also suspect that the body is a
tumbling asteroid in a non-principal axis rotation. These results supersede previous period solutions of 5 and 12.55 hours ().
Diameter and albedo According to the surveys carried out by the Japanese
Akari satellite and the
NEOWISE mission of NASA's
Wide-field Infrared Survey Explorer,
Inkeri measures between 15.206 and 31.86 kilometers in diameter and its surface has an
albedo between 0.033 and 0.2222. The
Collaborative Asteroid Lightcurve Link assumes an albedo of 0.10 and calculates a diameter of 18.35 kilometers based on an
absolute magnitude of 11.8. == Naming ==