A three-dimensional model of 82 Alkmene based on its lightcurve | |
| Discovery | |
|---|---|
| Discovered by | Karl Theodor Robert Luther |
| Discovery date | 27 November 1864 |
| Designations | |
| Pronunciation | /ælkˈmiːniː/ |
Named after | Alcmene |
| Main belt | |
| Adjectives | Alkmenean /ælkˈmiːniən/ |
| Orbital characteristics | |
| Epoch 9 December 2014 (JD 2457000.5) | |
| Aphelion | 3.3701 AU |
| Perihelion | 2.1609 AU |
| 2.7655 AU | |
| Eccentricity | 0.2186 |
| 4.60 yr | |
Average orbital speed | 17.70 km/s |
| 192.56° | |
| Inclination | 2.8286° |
| 25.507° | |
| 111.27° | |
| Physical characteristics | |
| Dimensions | 61±1.5 km (IRAS) |
| Mass | 2.4×1017 kg (assumed) |
| 12.999 h | |
| 0.208 | |
| S | |
| 8.40 | |
82 Alkmene is a main-belt asteroid. Alkmene was discovered by R. Luther on 27 November 1864 and named after Alcmene, the mother of Herakles in Greek mythology. Based on IRAS data, Alkmene is estimated to be about 61 kilometres (38 mi) in diameter. The presence of a satellite around the asteroid has been suggested based on 1985 lightcurve data.
Asteroid Alkmene occulted the apparent magnitude 7.5 star HIP 99229 in the constellation of Capricornus on 18 September 2014 around 06:41 UT (17 September 23:41 PDT) and was centered on Sacramento, CA. Alkmene projected an eclipse shadow that moves at about 3.2 km/s (2 mi/s). Asteroid occultations allow for accurate 2-dimensional mapping of an asteroids silhouette when observed by multiple telescopes separated by about 10 km (6.2 mi).