 | |
| Discovery | |
|---|---|
| Discovered by | Annibale de Gasparis |
| Discovery site | Naples Obs. |
| Discovery date | 29 July 1851 |
| Designations | |
| (15) Eunomia | |
| Pronunciation | /juːˈnoʊmiə/[1] |
Named after | Eunomia |
| Adjectives | Eunomian /juːˈnoʊmiən/[2] |
| Symbol | .svg){kind=small} (historical) |
| Orbital characteristics[3] | |
| Epoch July 01, 2021 (JD 2459396.5, heliocentric) | |
| Aphelion | 3.14 AU (469 Gm) |
| Perihelion | 2.15 AU (321 Gm) |
| 2.644 AU (395 Gm) | |
| Eccentricity | 0.186 |
| 4.30 yr (1571 d) | |
| 206° | |
| Inclination | 11.75° |
| 293° | |
| 99° | |
| Physical characteristics | |
| Dimensions | (357 × 255 × 212) ± 15 km[4] |
| 270±3 km[5] 268 km[4] 231.689 ± 2.234 km[3] | |
| Flattening | 0.47[a] |
| Mass | (30.5±1.9)×1018 kg[5] (31.8±0.3)×1018 kg[b][4] |
Mean density | 2.96±0.21 g/cm3[5] 3.14±0.53 g/cm3[4] |
| 6.083 h (0.2535 d)[3] | |
| 0.187[5] 0.25±4 geometric (0.84±0.02 BV, 0.45±0.02 UB)[3] | |
| S-type asteroid[3] | |
| 7.9[6] to 11.24 | |
| 5.41[3] | |
| 0.29″ to 0.085″ | |
15 Eunomia is a very large asteroid in the middle asteroid belt. It is the largest of the stony (S-type) asteroids, with 3 Juno as a close second. It is quite a massive asteroid, in 6th to 8th place (to within measurement uncertainties). It is the largest Eunomian asteroid, and is estimated to contain 1% of the mass of the asteroid belt.[7][8]
Eunomia was discovered by Annibale de Gasparis on July 29, 1851, and named after Eunomia, one of the Horae (Hours), a personification of order and law in Greek mythology. Its historical symbol is a heart with a star on top; it is in the pipeline for Unicode 17.0 as U+1CEC8 (.svg){kind=small}
).[9][10]
- ^ Noah Webster (1884) A Practical Dictionary of the English Language
- ^ "Eunomian". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
- ^ a b c d e f JPL data Retrieved 2021-09-29
- ^ a b c d Baer, James; Chesley, Steven R.; Matson, Robert D. (2011). "Astrometric Masses of 26 Asteroids and Observations on Asteroid Porosity". The Astronomical Journal. 141 (5): 143. Bibcode:2011AJ....141..143B. doi:10.1088/0004-6256/141/5/143. S2CID 121625885.
- ^ a b c d e P. Vernazza et al. (2021) VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis. Astronomy & Astrophysics 54, A56
- ^ Donald H. Menzel & Jay M. Pasachoff (1983). A Field Guide to the Stars and Planets (2nd ed.). Boston, MA: Houghton Mifflin. pp. 391. ISBN 0-395-34835-8.
- ^ Vitagliano, Aldo; Reiner M. Stoss (2006). "New mass determination of (15) Eunomia based on a very close encounter with (50278) 2000CZ12". Astronomy and Astrophysics. 455 (3): L29–L31. Bibcode:2006A&A...455L..29V. doi:10.1051/0004-6361:20065760.
- ^ Pitjeva, E. V. (2005). "High-Precision Ephemerides of Planets – EPM and Determination of Some Astronomical Constants" (PDF). Solar System Research. 39 (3): 176–186. Bibcode:2005SoSyR..39..176P. doi:10.1007/s11208-005-0033-2. S2CID 120467483. Archived from the original (PDF) on 31 October 2008. Retrieved 18 November 2008.
Eunomia 0.164E−11 solar masses; asteroid belt 15E−11 solar masses → 1.1%.
- ^ Bala, Gavin Jared; Miller, Kirk (18 September 2023). "Unicode request for historical asteroid symbols" (PDF). unicode.org. Unicode. Retrieved 26 September 2023.
- ^ Unicode. "Proposed New Characters: The Pipeline". unicode.org. The Unicode Consortium. Retrieved 6 November 2023.
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