So the Kiev astronomers makes these conclusions regarding the spinning UFOs:
"The objects of this group can be observed quite often. They move at a speed of 1-2 degrees per second. Their angular size is 8-9 arc minutes. A typical object of this group at distances of 1, 5 and 10 km will have a size of 4, 20 and 40 meters, and tangential veolcities of 18, 90 and 180 meters per sec.
Objects show variation in intensity and the area of the illuminated surface. Variations in intensity and area can be interpreted as (1) the object is rotating; (2) the object has a flattened shape with a aspect ratio of about 1:3."
And then they discuss other types of UFOs as well, of course.