11 Parthenope
Large main-belt asteroid
From Wikipedia, the free encyclopedia
11 Parthenope (/pɑːrˈθɛnəpi/ parth-EN-ə-pee) is a large, bright asteroid located in the main asteroid belt.
 Deconvolved VLT-SPHERE image of Parthenope | |
| Discovery | |
|---|---|
| Discovered by | Annibale de Gasparis |
| Discovery site | Naples Obs. |
| Discovery date | 11 May 1850 |
| Designations | |
| (11) Parthenope | |
| Pronunciation | /pɑːrˈθɛnəpi/ parth-EN-ə-pee[1] |
Named after | Parthenopē |
| Main belt | |
| Adjectives | Parthenopean (/ˌpɑːrθənəˈpiːən/ PARTH-ə-nə-PEE-ən) Parthenopian (/ˌpɑːrθəˈnoʊpiən/ PARTH-ə-NOH-pee-ən)[2] |
| Symbol | .svg){kind=small} or .svg){kind=small} (historical) |
| Orbital characteristics[3] | |
| Epoch 17.0 October 2024 (JD 2460600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 63626 days (174.20 yr) |
| Aphelion | 2.69732 AU (403.513 Gm) |
| Perihelion | 2.20942 AU (330.525 Gm) |
| 2.45337 AU (367.019 Gm) | |
| Eccentricity | 0.09943 |
| 3.84 yr (1403.6 d) | |
Average orbital speed | 19.02 km/s |
| 71.503° | |
| 0° 15m 23.342s / day | |
| Inclination | 4.63153° |
| 125.506° | |
| 2024-Jan-12 | |
| 196.071° | |
| Earth MOID | 1.197 AU (179.1 Gm) |
| Jupiter MOID | 2.54059 AU (380.067 Gm) |
| TJupiter | 3.483 |
| Physical characteristics | |
| Dimensions | 156 × 152 × 138 ± 6 km[4] |
| 149±2 km[4] 142.887±1.008 km[3] | |
| Flattening | 0.12[a] |
| Mass | (5.5±0.4)×1018 kg[4] 6.15×1018 kg[5] |
Mean density | 3.20±0.27 g/cm3[4] 3.28±0.20 g/cm3[5] |
Equatorial surface gravity | 0.0578 m/s2 |
Equatorial escape velocity | 0.0941 km/s |
| 13.7204 h (0.57168 d)[3] 13.72204±0.00001 h[4] | |
| 73°[4] | |
Pole ecliptic longitude | 312°±2°[4] |
Pole ecliptic latitude | 17°±4°[4] |
| 0.187 (calculated)[4] 0.191±0.021[3] | |
| Temperature | ~174 K |
| S-type asteroid[3] | |
| 8.68[6] to 12.16 | |
| 6.73[3] 6.55[4] | |
| 0.178" to 0.057" | |
History
Parthenope was discovered by Annibale de Gasparis on 11 May 1850, the second of his nine asteroid discoveries. It was named after Parthenopē, one of the Sirens in Greek mythology, said to have founded the city of Naples. De Gasparis "used his utmost endeavours to realise a 'Parthenope' in the heavens, such being the name suggested by Sir John Herschel on the occasion of the discovery of Hygiea in 1849".[7] Two symbols were proposed for Parthenope: a fish and a star (encoded in Unicode 17.0 as U+1CEC4 .svg){kind=small}
) while such symbols were still in use, and later a lyre (encoded in Unicode 17.0 as U+1F77A .svg){kind=small}
) in lists of symbols. Both are obsolete.[8][9][10]
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.[11]
Orbit
Parthenope orbits the Sun at an average distance (its semi-major axis) of 2.454 astronomical units (AU), with an orbital period of 3.845 years. Its distance from the Sun varies from 2.209 AU at its perihelion to 2.699 AU at its aphelion, indicated by its orbital eccentricity of 0.0998. Its orbit is inclined by 4.633° with respect to the ecliptic plane.[3] It is classified as a background asteroid, as it does not belong to any known asteroid family.[12]
Physical Characteristics
In 2007, Baer and Chesley calculated a higher mass and density for Parthenope based on perturbations by the 90 km asteroid 17 Thetis. Baer and Chesley calculated a mass of 6.3×1018 kg with a density of 3.3 g/cm3.[13] 2008 estimates by Baer suggest a mass of 6.15×1018 kg.[5] The 1997 and 2001 estimates by Viateau and Rapaport were closer to 5×1018 kg with a density of 2.7 g/cm3.[13]
Based upon a light curve that was generated from photometric observations of Parthenope at Pulkovo Observatory, it has a rotation period of 13.722 ± 0.001 hours and varies in brightness by 0.10 ± 0.0s in magnitude. The light curve displays three maxima and minima per cycle.[14]
