939 Isberga is a background asteroid from the inner asteroid belt near the region of the Flora family. It was discovered from Heidelberg on 4 October 1920 by Karl Wilhelm Reinmuth. As was his common practice, Reinmuth gave the asteroid a feminine name without reference to any specific person.
Isberga rotates quickly, with a period of 2.9173 hours. It is also suspected to be a binary asteroid, due to a second periodicity observed in its lightcurve from 24 Feb to 4 Mar 2006. The secondary object has an orbital period of 26.8 hours, but its size is undetermined. <sup>http://www.minorplanetobserver.com/mpb/MPB%2035-1.pdf</sup>