82 Alkmene
Alkmene (minor planet designation: 82 Alkmene) is a main-belt asteroid. Alkmene was discovered by R. Luther on 7 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. A satellite has been suggested based on 1985 lightcurve data.
A three-dimensional model of 82 Alkmene based on its light curve. | |
| Discovery | |
|---|---|
| Discovered by | Karl Theodor Robert Luther |
| Discovery date | 27 November 1864 |
| Designations | |
MPC designation | (82) Alkmene |
| Pronunciation | /ælkˈmiːniː/ |
Named after | Alcmene |
Minor planet category | Main belt |
| Adjectives | Alkmenean /ælkˈmiːniən/ |
| Orbital characteristics | |
| Epoch 9 December 2014 (JD 2457000.5) | |
| Aphelion | 3.3701 AU |
| Perihelion | 2.1609 AU |
Semi-major axis | 2.7655 AU |
| Eccentricity | 0.2186 |
Orbital period (sidereal) | 4.60 yr |
Average orbital speed | 17.70 km/s |
Mean anomaly | 192.56° |
| Inclination | 2.8286° |
Longitude of ascending node | 25.507° |
| 111.27° | |
| Physical characteristics | |
| Dimensions | 61±1.5 km (IRAS) |
| Mass | 2.4×1017 kg (assumed) |
Synodic rotation period | 12.999 h |
| 0.208 | |
| S | |
| 8.40 | |
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).