It's about 1/5 the diameter of Pluto (500km to Pluto's 2400), so quite small and definitely not a planet. It's interesting because it could give evidence about

It's about 1/5 the diameter of Pluto (500km to Pluto's 2400), so quite small and definitely not a planet. It's interesting because it could give evidence about the hypothetical ninth true planet-sized object that people have been hypothesizing for awhile.