 | |
| Discovery | |
|---|---|
| Discovered by | Norman Robert Pogson |
| Discovery date | 16 May 1866 |
| Designations | |
| (87) Sylvia | |
| Pronunciation | /ˈsɪlviə/ SIL-vee-ə[1] |
Named after | Rhea Silvia |
| A909 GA | |
| main belt · (outside core) Sylvia · Cybele | |
| Adjectives | Sylvian (/ˈsɪlviən/ SIL-vee-ən) |
| Orbital characteristics[2] | |
| Epoch 1 July 2021 (JD 2459396.5, heliocentric) | |
| Aphelion | 3.81 AU (560 Gm) |
| Perihelion | 3.15 AU (480 Gm) |
| 3.48 AU (520 Gm) | |
| Eccentricity | 0.094 |
| 6.5 a (2372 d) | |
Average orbital speed | 15.94 km/s[citation needed] |
| 213° | |
| 0° 9m 6.48s / day | |
| Inclination | 10.9° |
| 73° | |
| 263° | |
| Known satellites | 2 |
| Physical characteristics[3] | |
| Dimensions | (363 × 249 × 191) ±5 km (MPCD) or (374 × 248 × 194) ±5 km (ADAM) |
| 271±5 km (MPCD) or 274±5 km (ADAM) | |
| Volume | (10.5±0.2)×107 km3 (MPCD) or (10.8±0.2)×107 km3 (ADAM) |
| Mass | (14.76±0.06)×1018 kg[4] (14.6±0.1)×1018 kg[5] |
Mean density | 1.378±0.045 g/cm3[citation needed] |
| 0.2160 d (5.183641±0.000039 h) | |
North pole right ascension | 14.3°±5° |
North pole declination | +83.5°±5° |
Pole ecliptic latitude | +64.2°±5° |
Pole ecliptic longitude | 75.3°±5° |
| 0.0435 [6] | |
| X [7] | |
| 6.94 | |
87 Sylvia is one of the largest asteroids (approximately tied for 7th place, to within measurement uncertainties). It is the parent body of the Sylvia family and member of Cybele group located beyond the main asteroid belt (see minor-planet groups). Sylvia was the first asteroid known to possess more than one moon.
- ^ Noah Webster (1884) A Practical Dictionary of the English Language
- ^ JPL data Retrieved 2021-09-29
- ^ Carry, B.; et al. (June 2021). "Evidence for differentiation of the most primitive small bodies". Astronomy & Astrophysics. 650 A129. arXiv:2103.06349. doi:10.1051/0004-6361/202140342. ISSN 0004-6361.
- ^ F. Marchis; et al. (2005). "Discovery of the triple asteroidal system 87 Sylvia" (PDF). Nature. 436 (7052): 822–4. Bibcode:2005Natur.436..822M. doi:10.1038/nature04018. PMID 16094362. S2CID 4412813.
- ^ Margot and Brown (2001), from Jim Baer (2008). "Recent Asteroid Mass Determinations". Personal Website. Archived from the original on 2 July 2013. Retrieved 5 December 2008.
- ^ Supplemental IRAS Minor Planet Survey Archived 2009-08-17 at the Wayback Machine
- ^ PDS spectral class data Archived 2009-08-05 at the Wayback Machine