| Discovery[1] | |
|---|---|
| Discovered by | C. H. F. Peters |
| Discovery site | Litchfield Obs., Clinton |
| Discovery date | 28 June 1886 |
| Designations | |
| (259) Aletheia | |
| Pronunciation | /æləˈθiːə/[2] |
Named after | Aletheia[3] |
| A886 MA, 1947 LD | |
| main-belt | |
| Adjectives | Aletheian |
| Symbol | .svg) |
| Orbital characteristics[1] | |
| Epoch 27 June 2015 (JD 2457200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 117.00 yr (42,736 days) |
| Aphelion | 3.5353AU |
| Perihelion | 2.7347 AU |
| 3.1350 AU | |
| Eccentricity | 0.1276 |
| 5.55yr (2027.5 days) | |
| 71.260° | |
| Inclination | 10.813° |
| 86.864° | |
| 168.07° | |
| Earth MOID | 1.7207 AU |
| Physical characteristics | |
| Dimensions | 174.32±1.05 km[4] 190.05±6.82 km[5] |
| Mass | (7.79±0.43)×1018 kg[5] |
Meandensity | 2.16 ± 0.26[5] g/cm3 |
| 8.143h | |
| 0.0436 | |
| B–V = 0.698 U–B = 0.311 CP(Tholen),X(SMASS) | |
| 7.76 | |
259 Aletheia is a very largemain-beltasteroid that was discovered by German–American astronomerChristian Peters on June 28, 1886, atLitchfield Observatory, Clinton, New York. The dark and heterogeneously composedX-type (Tholen:CP-type) asteroid contains primitivecarbonaceous materials, responsible for its low albedo of 0.04. Aletheia measures about 185 kilometers in diameter and belongs to thelargest 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.[1]
Richard P. Binzel andSchelte 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.[6][7]
Lightcurve data has also been recorded by observers at the Antelope Hill Observatory, which has been designated as an official observatory by theMinor Planet Center.[8]
It is named after the Greek goddess of truth,Aletheia, the daughter of Zeus and one of the nurses of Apollo.[3]
