orbit diagram for the outer solar system
March 27, 2014

Newly Discovered Dwarf Planet Redefines Solar System’s Edge

Lee Rannals for redOrbit.com - Your Universe Online

Scientists have redefined the edge of the Solar System with the discovery of a new distant dwarf planet.

The scientists reported in the journal Nature this week that they found 2012 VP113 sitting beyond the known edge of the Solar System. The new dwarf planet is one of thousands of distant objects believed to have formed in the inner Oort cloud.

Not only does this new discovery bring into question the currently defined edge of the Solar System, but it also indicates the potential presence of an enormous planet that could be up to 10 times the size of Earth.

The observations and analysis were led and coordinated by Chadwick Trujillo of the Gemini Observatory in Hawaii and Scott Sheppard of the Carnegie Institution in Washington using the National Optical Astronomy Observatory’s 13-foot (4-meter) telescope in Chile.

"This is an extraordinary result that redefines our understanding of our Solar System," Linda Elkins-Tanton, director of Carnegie's Department of Terrestrial Magnetism, said in a statement.

Sedna was previously known as the farthest object in the Solar System, which was discovered beyond the Kuiper Belt edge back in 2003. 2012 VP113 now becomes the second known object to exist in this outer region, and likely the second known member of the hypothesized Oort cloud.

The new dwarf planet’s closest orbit to the Sun brings it about 80 times the distance of the Earth from the sun, or astronomical units (AU). To bring that into context, Pluto sits in the Kuiper Belt, which ranges from 30 to 50 AUs, while Sedna sits at 76 AUs.

"The search for these distant inner Oort cloud objects beyond Sedna and 2012 VP113 should continue, as they could tell us a lot about how our Solar System formed and evolved," Sheppard said in a statement.

2012 VP113 was discovered near its closest approach to the Sun, but the scientists said it has an orbit that goes out to hundreds of AU. The similarity between this dwarf planet and Sedna’s orbits are bringing scientists to believe that an unknown massive perturbing body could be helping to move these objects. The scientists suggest that a Super Earth could be creating this shepherding effect seen in the orbits.

"Some of these inner Oort cloud objects could rival the size of Mars or even Earth. This is because many of the inner Oort cloud objects are so distant that even very large ones would be too faint to detect with current technology," says Sheppard.

Acquisition of data used in this study was supported by NASA. Observations were partly obtained at Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, operated by the Association of Universities for Research in Astronomy, under contract with the National Science Foundation. This paper also includes data gathered with the 6.5-meter Magellan Telescopes located at Las Campanas Observatory, Chile.

Image 2 (below): These images show the discovery of 2012 VP113 taken about 2 hours apart on Nov. 5, 2012. The motion of 2012 VP113 stands out compared to the steady state background of stars and galaxies. Credit: Scott Sheppard/Carnegie Institution for Science