(528219) 2008 KV₄₂ (provisional designation: 2008 KV₄₂; nicknamed Drac)^[3] is a trans-Neptunian object and the first one with a retrograde orbit to be discovered. This retrograde motion with an orbital inclination of 103° suggests that it is the missing link between its source in the Hills cloud and Halley-type comets, thus providing further insight into the evolution of the outer Solar System. The object measures approximately 77 kilometers (48 miles) in diameter. With a semi-major axis of 42 AU, it takes about 269 years to complete an orbit around the Sun.

Officially discovered on 31 May 2008, the discovery was announced on 16 July 2008, by the Canada–France Ecliptic Plane Survey team led by Brett Gladman. The discovery team nicknamed 2008 KV₄₂ "Drac" after Count Dracula.

The discovery of 2008 KV₄₂ was announced on 16 July 2008 by the Canada–France Ecliptic Plane Survey team led by Brett Gladman from the University of British Columbia.^[9] The announcement was made during the "Asteroids, Comets, Meteors" meeting held in Baltimore, Maryland, followed by a Minor Planet Electronic Circular on the same day and an IAU Circular on 18 July. The discovery was made using images obtained on 31 May from the 3.5-meter Canada-France-Hawaii Telescope, followed by further observations until 8 July from the Whipple Observatory and Cerro Tololo.^[2][10]

The discovery team nicknamed 2008 KV₄₂ Drac because of its high inclination in reference to its orbital plane resembling Count Dracula's ability to walk on walls.^[11]

2008 KV₄₂ is the first trans-Neptunian object (TNO) with a retrograde orbit to be discovered. With a semi-major axis of 41.7 AU,^[4] it was discovered while at a distance of 32 AU and has a perihelion at roughly the distance of Uranus.

The object's 103° inclination makes its almost perpendicular to the ecliptic, and is, as of July 2017, one of only six objects known to have inclination and perihelion larger than 60° and 15 AU, respectively. The other six are: 2002 XU93, 2007 BP102, 2010 WG9, 2011 KT19, and 2014 LM28.^[12][13]

Its unusual orbit suggests that 2008 KV₄₂ may have been perturbed inwards from its source, most likely in the Hills cloud, by an unknown gravitational disturbance. Its discovery may reveal the source regions for Halley-type comets which also have an retrograde orbit, but their origin remains unknown. 2008 KV₄₂ itself is believed to be in an intermediate stage towards becoming a comet, thus helping to further explain the formation and evolution of the outer Solar System.^[14][15][3]

• List of trans-Neptunian objects
• (471325) 2011 KT₁₉ ("Niku")