2012 VP113 orbit (orange) compared with Sedna’s orbit (red).
Graphics from Scott S. Sheppard website.

2012 VP113

Scientists using ground-based observatories have discovered an object that is believed to have one of the most distant orbit found beyond the known edge of our solar system. Named 2012 VP113, it may be a dwarf planet. A dwarf planet is an object in orbit around the sun that is large enough to have its own gravity pull itself into a nearly round or spherical shape.

The discovery shows the outer reaches of our solar system are not an empty wasteland as once was thought. There may be many more inner Oort Cloud bodies awaiting discovery.

2012 VP113's closest orbit point to the sun brings it to about 80 times the distance of the Earth from the sun, a measurement referred to as an astronomical unit or AU. The rocky planets and asteroids exist at distances ranging between .39 and 4.2 AU. Gas giants are found between 5 and 30 AU, and the Kuiper Belt (composed of hundreds of thousands of icy objects, including Pluto) ranges from 30 to 50 AU. In our solar system there is a distinct edge at 50 AU. Until 2012 VP113 was discovered, only Sedna, with a closest approach to the Sun of 76 AU, was known to stay significantly beyond this outer boundary for its entire orbit.

Measurements of the color of 2012 VP113 show it is moderately red. This is typical of objects in the Kuiper Belt and suggests that 2012 VP113 formed in the gas giant region of the solar system before being ejected to the inner Oort Cloud. Assuming that 2012 VP113 reflects 15 percent of the light falling on it, it is about 450 km (280 miles) in diameter.

Scientists believe that about 900 objects with orbits like Sedna and 2012 VP113 with sizes larger than 1,000 km (621 miles) may exist. The small worlds are likely one of hundreds of thousands of distant objects that inhabit the region in our solar system scientists refer to as the inner Oort cloud. The total population of the inner Oort cloud is likely bigger than that of the Kuiper Belt and main asteroid belt.

Some of the inner Oort Cloud objects could rival the size of Mars or even Earth, but inner Oort Cloud objects are so distant that even very large ones would be too faint to detect with current technology.

Both Sedna and 2012 VP113 were found near their closest approach to the sun, but they both have orbits that go out to hundreds of AU, at which point they would be too faint to discover. The similarity in the orbits found for Sedna, 2012 VP113 and a few other objects near the edge of the Kuiper Belt suggests that Sedna's and new object's orbits might be influenced by the potential presence of a yet unseen planet perhaps up to 10 times the size of Earth.

Further studies of this deep space arena will continue.

2012 VP113 was first observed on 5 November 2012 by Chadwick Trujillo of the Gemini Observatory in Hawaii and Scott Sheppard of the Carnegie Institution in Washington. They used the National Optical Astronomy Observatory's 4 meter (13 foot) telescope in Chile to discover 2012 VP113. The Magellan 6.5 meter (21 foot) telescope at Carnegie's Las Campanas Observatory in Chile was used to determine the orbit of 2012 VP113 and obtain detailed information about its surface properties.

2012 VP113 is a provisional designation that means the discovery year and the discovered object number in November first half. This small body will later be named officially by the International Astronomical Union.

These images show the discovery of 2012 VP113 taken about 2 hours apart on Nov. 5, 2012.
Image Credit: Scott Sheppard/Carnegie Institution for Science