54509 YORP was discovered by LINEAR some time in 2000 an was named after the YORP effect, shortened name for YarkovskyO'KeefeRadzievskiiPaddack effect.
54509 YORP, provisional designation 2000 PH5, is an Earth co-orbital asteroid discovered on 3 August 2000 by the Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) Team at Lincoln Laboratory Experimental Test Site in Socorro, New Mexico. Measurements of the rotation rate of this object provided the first observational evidence of the YORP effect, hence the name of the asteroid. The YarkovskyO'KeefeRadzievskiiPaddack effect, or YORP effect for short, changes the rotation state of a small astronomical body  that is, the body's spin rate and the obliquity of its pole(s)  due to the scattering of solar radiation off its surface and the emission of its own thermal radiation. 
