1599 Giomus is a main belt asteroid with an estimated diameter of about 15 km. It was discovered on November 17, 1950 by Boyer, L. at Algiers. The semi-major axis is 3.11 AU, the eccentricity is 0.144 and the inclination is 6.09 degrees.
I observed this asteroid on two consecutive nights in June 2009 when it was in the same field as another asteroid I was working on. The resulting data was very noisy but some sort of lightcurve was derived with a period of about 6.46 hours. However this result is very uncertain and more work is needed on this asteroid.