[14] The stony S-type asteroid has a rotation period of 5.1 hours and measures approximately 34 kilometers (21 miles) in diameter.

[1] In March 2011, a rotational lightcurve of Neujmina was obtained from photometric observations at the Oakley Southern Sky Observatory (E09) in Australia.

Lightcurve analysis gave a well-defined rotation period of 5.0844 hours with a brightness variation of 0.20 magnitude (U=3).

[12][13] According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Neujmina measures between 30.99 and 39.246 kilometers in diameter and its surface has an albedo between 0.0999 and 0.138.

[5][6][7][8][9][10] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.1270 and a diameter of 34.80 kilometers based on an absolute magnitude of 10.15.