| Minorplanet: | yes |
| Background: |
|
| 405 Thia | |
| Discovered: | 23 July 1895 |
| Mpc Name: | (405) Thia |
| Pronounced: | [1] |
| Alt Names: | 1895 BZ |
| Epoch: | 2023-Feb-25 (JD 2460000.5) |
| Observation Arc: | 123.54 years |
| Uncertainty: | 0 |
| Semimajor: | 2.5861AU |
| Perihelion: | 1.9592AU |
| Time Periastron: | 2 June 2023 |
| Aphelion: | 3.2145abbr=onNaNabbr=on |
| Eccentricity: | 0.24341 |
| Period: | 4.16 yr (1518.3 d) |
| Inclination: | 11.937° |
| Asc Node: | 255.19° |
| Arg Peri: | 308.65° |
| Moid: | 0.975AU |
| Dimensions: | 122.14 ± 7.69 km |
| Density: | 1.44 ± 0.30 g/cm3 |
| Rotation: | 10.08abbr=onNaNabbr=on |
| Abs Magnitude: | 8.65 |
| Mean Motion: | / day |
405 Thia is a very large main-belt asteroid. 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.[2]
In 2002, the asteroid was detected by radar from the Arecibo Observatory at a distance of 1.31 AU. The resulting data yielded an effective diameter of . NEOWISE data suggests the asteroid is 110 km in diameter.
On 4 May 1990 Thia passed 0.969AU from Earth and will pass that close again on 29 April 2073.
405 Thia currently has a Minimum orbit intersection distance with Earth of 0.975AU and on 20 March 2023 will be 1.057abbr=unitNaNabbr=unit from Earth. Then on 2 June 2023 the asteroid will reach perihelion (closest approach to the Sun).
| 2023-03-20 19:40 | 1.057abbr=unitNaNabbr=unit | 2.006AU | 6.8 | 23.3 | ± 16 km | Horizons |