| Minorplanet: | yes |
| 259 Aletheia | |
| Background: |
|
| Discovery Ref: |   |
| Discovered: | 28 June 1886 |
| Mpc Name: | (259) Aletheia |
| Alt Names: | A886 MA, 1947 LD |
| Pronounced: | [1] |
| Adjective: | Aletheian |
| Orbit Ref: |   |
| Epoch: | 27 June 2015 (JD 2457200.5) |
| Uncertainty: | 0 |
| Observation Arc: | |
| Perihelion: | 2.7347 AU |
| Semimajor: | 3.1350 AU |
| Eccentricity: | 0.1276 |
| Period: | 5.55 yr (2027.5 days) |
| Inclination: | 10.813° |
| Asc Node: | 86.864° |
| Arg Peri: | 168.07° |
| Moid: | 1.7207 AU |
| Dimensions: | [2] km |
| Mass: | kg |
| Density: | 2.16 ± 0.26 g/cm3 |
| Albedo: | 0.0436 |
| Abs Magnitude: | 7.76 |
259 Aletheia is a very large main-belt asteroid that was discovered by German–American astronomer Christian Peters on June 28, 1886, at Litchfield Observatory, Clinton, New York. The dark and heterogeneously composed X-type (Tholen: CP-type) asteroid contains primitive carbonaceous materials, responsible for its low albedo of 0.04. Aletheia measures about 185 kilometers in diameter and belongs to the largest asteroids of the main-belt. It has a semi-major axis of 3.1 AU and an orbit inclined by 11 degrees with a period of 5.55 years.
Richard P. Binzel and Schelte Bus further added to the knowledge about this asteroid in a lightwave survey published in 2003. This project was known as Small Main-belt Asteroid Spectroscopic Survey, Phase II or SMASSII, which built on a previous survey of the main-belt asteroids. The visible-wavelength (0.435-0.925 micrometre) spectra data was gathered between August 1993 and March 1999.[3] [4]
Lightcurve data has also been recorded by observers at the Antelope Hill Observatory, which has been designated as an official observatory by the Minor Planet Center.[5]
It is named after the Greek goddess of truth, Aletheia, the daughter of Zeus and one of the nurses of Apollo.
