Claim: 2015 TH367, discovered by D. J. Tholen an French astronomer, has a poorly understood orbit and hasn't been observed since October 2016.
Evidence: 2015 TH367 was first observed by Scott Sheppard, Chad Trujillo, and David Tholen on 13 October 2015 using the Subaru Telescope, a large reflecting telescope at the Mauna Kea Observatories on the summit of Mauna Kea with a primary mirror 8.2 meters (27 ft) in diameter. D. J. Tholen
S. S. Sheppard
C. W. Trujillo