From HandWiki - Reading time: 4 min
A three-dimensional model of 40 Harmonia based on its light curve on the top and an image of 40 Harmonia on the bottom. | |
| Discovery | |
|---|---|
| Discovered by | H. Goldschmidt |
| Discovery date | March 31, 1856 |
| Designations | |
| (40) Harmonia | |
| Pronunciation | /hɑːrˈmoʊniə/[1] |
| Named after | Harmonia |
| 1950 XU | |
| Minor planet category | Main belt |
| Orbital characteristics[2] | |
| Epoch December 31, 2006 (JD 2454100.5) | |
| |{{{apsis}}}|helion}} | 355.021 Gm (2.373 AU) |
| |{{{apsis}}}|helion}} | 323.537 Gm (2.163 AU) |
| 339.279 Gm (2.268 AU) | |
| Eccentricity | 0.046 |
| Orbital period | 1,247.514 d (3.42 a) |
| Mean anomaly | 249.120° |
| Inclination | 4.256° |
| Longitude of ascending node | 94.287° |
| 268.988° | |
| Physical characteristics | |
| Dimensions | 111.251 ± 0.391 km[2] |
| Mass | (2.206 ± 0.612/0.42)×1018 kg[3] |
| Mean density | 2.867 ± 0.795/0.546 g/cm3[3][lower-alpha 1] |
| Rotation period | 0.3712 d (8.909 h)[4] |
| Geometric albedo | 0.242[5] |
| S | |
| Apparent magnitude | 9.31 (brightest) |
| Absolute magnitude (H) | 6.55[2] |
40 Harmonia is a large main-belt asteroid. It was discovered by German-French astronomer Hermann Goldschmidt on March 31, 1856,[6] and named after Harmonia, the Greek goddess of harmony. The name was chosen to mark the end of the Crimean War.
The asteroid is orbiting the Sun with a period of 3.42 years and a relatively low eccentricity of 0.046. It has a cross-sectional size of 107.6 km. The spectrum of 40 Harmonia matches an S-type (silicate) in the Tholen classification system, and is similar to primitive achondrite meteorites.[7] Photometric observations at the Organ Mesa Observatory in Las Cruces, New Mexico during 2008–09 were used to generate a light curve that showed four unequal minima and maxima per cycle. The curve shows a period of 8.909 ± 0.001 hours with a brightness variation of 0.28 ± 0.02 in magnitude. This result is compatible with previous studies.[4]
Speckle interferometric observations carried out with the Nicholas U. Mayall Telescope at the Kitt Peak National Observatory during 1982–84 failed to discover a satellite companion.[8] In 1988 a search for satellites or dust orbiting this asteroid was performed using the UH88 telescope at the Mauna Kea Observatories, but the effort came up empty.[9]