Smetana is an assumed
E-type asteroid.
Lightcurves Between 2006 and 2012, several rotational
lightcurves of
Smetana were obtained from photometric observations by American astronomer
Brian Warner at his Palmer Divide Observatory () and CS3–Palmer Divide Station () in Colorado and California, respectively. Lightcurve analysis gave a
rotation period between 2.4801 and 2.498 hours with a brightness variation of between 0.12 and 0.16
magnitude ().
Satellite During Warner's photometric observations in 2012, it was revealed that
Smetana is a synchronous
binary asteroid with an orbiting
minor-planet moon. The satellite orbits its primary every 22.43 hours and measures approximately 0.63 kilometers in diameter. However the binary status of
Smetana has not yet been confirmed unambiguously, since observations in 2016 could not clearly detect any mutual
occultation and eclipsing events.
Diameter and albedo According to the surveys carried out by the
NEOWISE mission of NASA's
Wide-field Infrared Survey Explorer,
Smetana measures 3.131 kilometers in diameter and its surface has an
albedo of 0.544. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.30 – a compromise value between 0.4 and 0.2, corresponding to the Hungaria asteroids both as family and orbital group – and calculates a diameter of 3.85 kilometers with an
absolute magnitude of 14.0. == Naming ==