In “Pluto and Eris found to be of equal measure, (ABC News 27 October 2011), Stuart Gary reports:
The distant frozen world of Eris, once considered to be the largest of the dwarf planets, may actually be the same size as Pluto.
Orbits the sun.
Reporting in the journal Nature, Sicardy and colleagues determine that Eris is about 1163 kilometres wide, which makes it roughly the same size as Pluto – estimated to be between 1150 and 1200 kilometres in diameter – and far smaller than earlier estimates of around 1500 kilometres.