1613 Smiley (1950 SD) is a main-beltasteroid discovered on September 16, 1950 by S. Arend at Uccle. It is named after American astronomer Charles Hugh Smiley (1903-1977). The name 'Smiley' was going to be used on trans-neptunian object 1992 QB1 but was declined due to the fact that two asteroids may not have the same name.
Photometric observations of the asteroid during 2006 at the Palmer Divide Observatory in Colorado Springs, Colorado, were used to generate a light curve with a lengthy period of 81.0 ± 0.1 hours and a variation in brightness of 0.30 ± 0.02 magnitude.
^Warner, Brian D. (September 2006), "Asteroid lightcurve analysis at the Palmer Divide Observatory - late 2005 and early 2006", Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers33: 58–62, Bibcode:2006MPBu...33...58W.