53 Kalypso
Kalypso (minor planet designation: 53 Kalypso) is a large and very dark main belt asteroid that was discovered by German astronomer Robert Luther on April 4, 1858, at Düsseldorf. It is named after Calypso, a sea nymph in Greek mythology, a name it shares with Calypso, a moon of Saturn.
Three-dimensional model of 53 Kalypso created based on light-curve. | |
| Discovery | |
|---|---|
| Discovered by | Karl Theodor Robert Luther |
| Discovery date | 4 April 1858 |
| Designations | |
MPC designation | (53) Kalypso |
| Pronunciation | /kəˈlɪpsoʊ/ |
Named after | Calypso |
Minor planet category | Main belt |
| Adjectives | Kalypsonian /kælɪpˈsoʊniən/ Kalypsoian /kælɪpˈsoʊ.iən/ |
| Orbital characteristics | |
| Epoch December 31, 2006 (JD 2454100.5) | |
| Aphelion | 471.807 Gm (3.154 AU) |
| Perihelion | 311.998 Gm (2.086 AU) |
Semi-major axis | 391.903 Gm (2.620 AU) |
| Eccentricity | 0.204 |
Orbital period (sidereal) | 1548.736 d (4.24 a) |
Mean anomaly | 98.113° |
| Inclination | 5.153° |
Longitude of ascending node | 143.813° |
| 312.330° | |
| Physical characteristics | |
| Dimensions | 115.4 km |
| Mass | (1.294 ± 0.520/0.412)×1018 kg |
Mean density | 1.625 ± 0.653/0.517 g/cm3 |
Synodic rotation period | 9.036 h |
| 0.040 | |
| 8.81 | |
The orbit of 53 Kalypso places it in a mean motion resonance with the planets Jupiter and Saturn. The computed Lyapunov time for this asteroid is 19,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets.
Photometric observations of this asteroid during 2005–06 gave a light curve with a period of 18.075 ± 0.005 hours and a brightness variation of 0.14 in magnitude. In 2009, a photometric study from a different viewing angle was performed at the Organ Mesa Observatory in Las Cruces, New Mexico, yielding a rotation period of 9.036 ± 0.001 with a brightness variation of 0.14 ± 0.02 magnitude. This is exactly half of the 2005–06 result. The author of the earlier study used additional data observation that favored the 9.036 hour period. The discrepancy was deemed a consequence of viewing the asteroid from different longitudes.
Kalypso has been studied by radar.