While processing CCD images of galaxies of the SINGS project, Juan Carlos Muñoz Mateos has found the visible traces of a celestial object moving across the field of the nearby galaxy M100. The animated picture shows the consecutive images taken in B, V, R and I bands. The celestial body is clearly moving with respect to the background stars and galaxies. After a careful search in the JPL Small-Body Database the unidentified object has been found to be 1996 AU3.

This object was originally discovered by S. Ueda and H. Kaneda in 1996. It belongs to the main asteroid belt between Mars and Jupiter, completing a whole orbit each 4.3 years. The following diagram depicts the tridimensional orbit of this asteroid.