268 Adorea
Main-belt asteroid
From Wikipedia, the free encyclopedia
268 Adorea is a very large main belt asteroid, about 140 km (87 mi) in width. It was discovered by Alphonse Borrelly on 8 June 1887 in Marseille. This asteroid is a member of the Themis family[3] and is classified as a primitive carbonaceous F-type/C-type asteroid. It is orbiting the Sun at a distance of 3.09 AU with an orbital eccentricity (ovalness) of 0.14 and a period of 5.44 yr. The orbital plane is tilted at an angle of 2.44° to the plane of the ecliptic.[1]
Orbital diagram | |
| Discovery | |
|---|---|
| Discovered by | Alphonse Borrelly |
| Discovery date | 8 June 1887 |
| Designations | |
| (268) Adorea | |
| Pronunciation | /ÉËdÉËriÉ/ |
Named after | adorea liba (spelt cakes) |
| A887 LA | |
| Main belt (Themis) | |
| Adjectives | Adorean /ÉËdÉËriÉn/ |
| Orbital characteristics[1] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 39,920 d (109.3 yr) |
| Aphelion | 3.515 AU (525.8 Gm) |
| Perihelion | 2.668 AU (399.2 Gm) |
| 3.092 AU (462.5 Gm) | |
| Eccentricity | 0.13689 |
| 5.44 yr (1,985.5 d) | |
| 302.257° | |
| 0° 10m 52.748s / day | |
| Inclination | 2.44010° |
| 120.914° | |
| 69.5742° | |
| Physical characteristics | |
| 144.585±0.892 km[1] 139.57±3.31 km[2] | |
| Mass | (2.228 ± 0.919/0.718)Ã1018 kg[2] |
Mean density | 1.565 ± 0.645/0.505 g/cm3[2] |
| 7.80 h (0.325 d) | |
| 0.041±0.007[1] | |
| FC | |
| 8.67[1] | |
From 23 February until 2 March 2006, photometric measurements were taken of the asteroid. These were used to produce a light curve showing a rotation period of 7.80±0.02 h with a brightness variation of 0.16±0.03 in magnitude. This result is consistent with some, but not all previous results. Some studies had suggested a longer rotation period of 15.959 h; double the time measured. However, the new data is inconsistent with the longer period.[4]
In May 1979, 268 Adorea was positioned in proximity of the galaxy NGC 4517 and as a bright new light source it was identified as a potential supernova. However, the light was missing from a second photographic plate taken ten days later, and the source was soon identified as the asteroid.[5]
The name refers to adorea liba, the Latin name for spelt cakes produced from meal and salt offered by the Romans as a sacrifice; the name was controversial among astronomers, as all previous asteroids had been named for humans or mythological figures.[6][7]
