The date of the official discovery was later set to 27 December 2009, and credited to astronomers of the Spacewatch program conducted at the Kitt Peak National Observatory near Tucson, Arizona, in the United States.
During this time, and with only two observations taken on the same day, it was thought to be a trans-Neptunian object with a semi-major axis of 46 AU.
[2][7] Michael Brown listed it as a likely a dwarf planet on his website with an estimated diameter of 555 kilometers based on an absolute magnitude of 4.6 and an assumed albedo of 0.09.
In 2012, it was finally rediscovered under its principal designation, reclassified as a small main-belt asteroid, and numbered two years later (see below).
[6]: 23 Based on a generic magnitude-to-diameter conversion, 2012 SQ31 measures 690 meters for an absolute magnitude of 18.0 and an assumed albedo of 0.24.