Infrared observations of the extinct cometary candidate minor planet (3200) 1983TB

Abstract

The discovery of Apollo asteroid (3200) 1983TB in an orbit virtually coincident with the Geminid meteor stream has raised the possibility that it is an extinct cometary nucleus. Infrared observations between 1 and 20 µm are presented from which an albedo of 0.11±0.02 and diameter of (4.70±0.5) km are derived. Both the thermal spectrum (which implies a surface of relatively high conductivity) and the reflected colors, disagree with the expected properties of an extinct cometary nucleus. However, the blue JHK colors and moderate albedo, when combined with optical data, show 1983TB to be a unique object among the known Apollo asteroids.