The Rotation State of 4015 Wilson-Harrington: Revisiting Origins for the Near-Earth Asteroids

Abstract CCD photometry performed on the comet/asteroid transition object 4015 Wilson-Harrington during its most recent apparition has provided a new rotational lightcurve with a standard double-peaked rotational period of 6.1 ± 0.05 hr and an amplitude of 0.2 magnitudes. The size, rotation period, and lightcurve amplitude of this object are all similar to values found for near-earth asteroids (NEA) and small main-belt asteroids. However, these values vary significantly from those of any previously well-studied cometary nuclei. In short, the range in cometary nuclear properties is greater than that indicated by the comets studied previously and although the statistics are still poor, the size and rotational properties of 4015 Wilson-Harrington do suggest that some fraction of NEAs are of cometary origin.