Naganuma is an assumed
S-type asteroid, which agrees with its determined
geometric albedo (see below).
Rotation period In November 2005, a rotational
lightcurve of Naganuma was obtained from
photometric observations by
Donald Pray at the Carbuncle Hill Observatory in Rhode Island, United States. Lightcurve analysis gave a
rotation period of hours with a brightness amplitude of 0.20
magnitude (). Concurring periods of 2.58348, 2.5835 and 2.587 hours were also determined by Vladimir Benishek at Sopot Astronomical Observatory and
Petr Pravec at
Ondřejov Observatory ().
Diameter and albedo According to the survey carried out by the
NEOWISE mission of NASA's
Wide-field Infrared Survey Explorer (WISE), Naganuma measures 4.36 kilometers in diameter and its surface has an
albedo if 0.256. The
Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE-albedo of 0.20 and calculates diameter of 4.34 kilometers based on an
absolute magnitude of 14.16. == Notes ==