Scott Sheppard and Chad Trujillo Discover a Dwarf Planet on the Fringe of the Solar System

2012 VP 113
2012 VP113 Inner Oort Cloud Object Discovery Images (Credit: Scott Sheppard, DTM)
Friday, March 28, 2014 

How big is the Solar System? After the discovery of the dwarf planet Sedna ten years ago, the question of what lies beyond the edge of the Solar System has been continuously sought out by the world’s brightest astronomers. This week, that question gets closer to an answer. DTM staff scientist Scott Sheppard and co-discoverer Chad Trujillo of the Gemini Observatory in Hilo, Hawaii, report in Nature their discovery of the dwarf planet 2012 VP113 orbiting the Sun far beyond Pluto in the most distant orbital trajectory around the Sun known.

Sedna and 2012 VP 113 Scott Sheppard
This diagram for the outer solar system shows the orbits of Sedna (in orange) and 2012 VP113 (in red). The sun and terrestrial planets are at the center, surrounded by the orbits (in purple) of the four giant planets — Jupiter, Saturn, Uranus and Neptune. The Kuiper belt, which includes Pluto, is shown by the dotted light blue region. (Credit: Scott Sheppard, DTM)

This dwarf planet, nicknamed VP for short, or ‘Biden’ – after US Vice-President Joe Biden, is approximately 250 miles in diameter. Sheppard and Trujillo discovered it in November 2012 using the Dark Energy Camera at the Cerro Tololo Inter-American Observatory in Chile. In order to see objects so far away from Earth, astronomers take three pictures of the sky, approximately an hour apart, and create a time-lapse movie with the images. If an object in the time-lapse changes location, then it’s worth investigating further. Sheppard and Truijillo were lucky, and discovered the moving object, VP, in the fifth snapshot of the hundreds they were about to take.

VP lies beyond the classical planetary portion of the Solar System among the icy bodies in the Kuiper Belt. Its surface is most likely covered in ice with a temperature of minus 430 degrees Fahrenheit. Listen to Sheppard discuss the supposed origin of VP on NPR’s All Things Considered here.

This discovery, along with Sedna, is reshaping the idea of how the Solar System came to be and where its boundaries really are. Read the full article in Nature here.