60558 Echeclus is only the second comet (after Chiron) that was named as a minor planet, rather than after the name of its discoverer. Chiron is also a centaur; other centaurs are being observed for signs of a cometary coma.
Besides Chiron, three other objects are cross-listed as both comets and minor planets: 7968 Elst–Pizarro (133P/Elst–Pizarro), 4015 Wilson–Harrington (107P/Wilson–Harrington), and 118401 LINEAR (176P/LINEAR).
On 30 December 2005, when 13.1 AU from the Sun, a large chunk of Echeclus was observed to break off, causing a great cloud of dust. Astronomers have speculated this could have been caused by an impact or by an explosive release of volatile substances.
Echeclus appears to have outburst again around June 2011 when it was 8.5 AU from the Sun. On 24 June 2011, follow up imaging with the 2 meter Haleakala-Faulkes Telescope South showed the coma of Echeclus to be very close to the sky background limit.
Echeclus came to perihelion in April 2015.
Centaurs have short dynamical lives due to strong interactions with the giant planets. Echeclus is estimated to have an orbital half-life of about 610,000 years.