13643 Takushi is a main belt asteroid with an estimated diameter of 5 km. It was discovered on April 21, 1996 by H. Abe at Yatsuka. The semi-major axis is 2.45 AU, the eccentricity is 0.112 and the inclination is 13.83 degrees.
Observations of this asteroid were made on five nights during December/January 2011/2012. Analysis of the data showed the asteroid to be a relatively slow rotator with a period of around 83.838 hours. The amplitude was around 1.00 mag, however these results are tentative as no definite maximum or minimum was observed.