Hubble Images of 2007 OR10

This sequence of images, taken by the Hubble Space Telescope's Wide Field Camera 3, shows a moon circling the dwarf planet 2007 OR 10 . The top four images were taken Nov. 6, 2009; the bottom four, on Sept. 18, 2010.

As 2007 OR 10 orbits the sun, it changes position with respect to the background stars (the bright objects that change from panel to panel). The snapshots reveal that the moon moves with the dwarf planet, proving that it is gravitationally bound to the larger body.

2007 OR 10 is the third-largest known dwarf planet, behind Pluto and Eris, and the largest unnamed world in the solar system. The pair is located in the Kuiper Belt, a realm of icy debris left over from the solar system's formation.

The dwarf planet is about 950 miles across; the moon is estimated to be 150 miles to 250 miles in diameter. 2007 OR 10 , like Pluto, follows an eccentric orbit, but it is currently three times farther than Pluto is from the sun.

About the colours

These images were taken with HST's WFC3/UVIS instrument using the F606W, F775W, and F814W filters. Color was added to the grayscale images using a blue color mapping. Blue: F606W+F775W+F814W (B)

About the data

HST data from proposals 11644 , M. Brown (Caltech) and 12234 , W. Fraser (Herzberg Institute of Astrophysics) were used in the analysis.