(523731) 2014 OK394

Did You Know?

• Johnstons Archive estimates a diameter of 217 km assuming a geometric albedo of 0.126, whereas Michael E. Brown estimates a diameter of 160 km for an assumed albedo of 0.20.
• A 2024 study led by Audrey Thirouin and Scott Sheppard found that it exhibits little variability in brightness over four hours of observations, with a light curve amplitude of roughly 0.05 magnitude.

Discovery

(523731) 2014 OK394 was discovered on two separate occasions, earning it two different provisional designations. Its first sighting came on 20 September 1995, when astronomers Nichole Danzl and Arianna Gleason, working with the Spacewatch survey at Kitt Peak Observatory in Arizona, observed it. Over the next 36 days, they recorded only 14 observations, ending on 26 October 1995. After that, the object vanished from view and became a lost minor planet. The Minor Planet Center published these initial discovery observations on 11 June 1999, assigning a provisional designation. Because so few observations existed, its orbit was highly uncertain. Astronomers considered several possibilities: it could be one of the largest known centaurs, an object that had temporarily brightened, or simply a false positive from image noise. On 8 October 2010, the Pan-STARRS 1 survey at Haleakalā Observatory in Hawaii unknowingly rediscovered it. Pan-STARRS tracked the object until 2015, and the MPC announced this second discovery with a new provisional designation on 17 July 2016. Once the orbit was reliably determined in 2018, the MPC credited Pan-STARRS as the official discoverer. On 30 November 2020, amateur astronomers S. Deen and K. Ly recognized that this object was the same as the one from 1995. The MPC published this identification on 27 January 2021, and subsequently changed the official discoverer back to Spacewatch.

Classification and orbit

This Kuiper belt object takes 278 years to circle the Sun, averaging 42.6 astronomical units away. Its path is slightly oval, with an eccentricity of 0.17, and tilts 4 degrees from the ecliptic. The distance from the Sun varies between 35.5 AU at its closest and 49.7 AU at its farthest. It is locked in a 3:5 orbital resonance with Neptune, meaning three of its orbits match five of Neptune's. The closest its orbit comes to Neptune's path is about 5.8 AU.