It is classified as a C-type asteroid and is probably composed of carbonaceous material.
This object was discovered by Auguste Charlois on July 23, 1895, in Nice, and was named after Theia (sometimes written Thea or Thia), a Titaness in Greek mythology.
[4] In 2002, the asteroid was detected by radar from the Arecibo Observatory at a distance of 1.31 AU.
405 Thia currently has a Minimum orbit intersection distance with Earth of 0.976 AU (146.0 million km; 380 LD)[2].
On 2 June 2023 the asteroid reached perihelion (closest approach to the Sun).