311P/PanSTARRS

Three-dimensional models constructed by Jessica Agarwal of the Max Planck Institute for Solar System Research in Lindau, Germany, showed that the tails could have formed by a series of periodic impulsive dust-ejection events, radiation pressure from the Sun then stretched the dust into streams.

Precovery images from the Sloan Digital Sky Survey from 2005 were found, showing negligible cometary activity in 2005.

Physical characteristics

The asteroid has a radius of about 240 m (790 ft). The first images taken by Pan-STARRS revealed that the object had an unusual appearance: asteroids generally appear as small points of light, but P/2013 P5 was identified as a fuzzy-looking object by astronomers. The multiple tails were observed by the Hubble Space Telescope on 10 September 2013, Hubble later returned to the asteroid on 23 September, its appearance had totally changed. It looked as if the entire structure had swung around. The Hubble Space Telescope continued to track the object through 11 February 2014. The comet-like appearance has resulted in the asteroid being named as a comet. The object has a low orbital inclination and always stays outside the orbit of Mars.