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 | |
Orbital characteristics [1] | |
Epoch 27 June 2015 ( JD 2457200.5) | |
Uncertainty parameter 0 | |
Observation arc | 117.00 yr (42,736 days) |
Aphelion | 3.5353 AU |
Perihelion | 2.7347 AU |
3.1350 AU | |
Eccentricity | 0.1276 |
5.55 yr (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] |
Mean
density | 2.16 ± 0.26 [5] g/cm3 |
8.143 h | |
0.0436 | |
B–V = 0.698 U–B = 0.311 CP ( Tholen), X ( SMASS) | |
7.76 | |
Aletheia ( minor planet designation: 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: C P-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. [1]
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. [6] [7]
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. [8]
It is named after the Greek goddess of truth, Aletheia, the daughter of Zeus and one of the nurses of Apollo. [3]