2015 TH367, discovered by D. J. Tholen an American astronomer, has a poorly understood orbit and hasn't been observed since October 2016.
D. J. Tholen
S. S. Sheppard
C. W. Trujillo David James Tholen (born 1955) is an American astronomer at the Institute for Astronomy of the University of Hawaii. The object has not been observed since October 2016. The precise distance of 2015 TH367 still remains unknown due to its poorly understood orbit. 
