Astronomy:93 Minerva
 A three-dimensional model of 93 Minerva based on its light curve on the top and an image of the asteroid on the bottom. | |
| Discovery | |
|---|---|
| Discovered by | James Craig Watson |
| Discovery site | Ann Arbor, Michigan |
| Discovery date | 24 August 1867 |
| Designations | |
| (93) Minerva | |
| Pronunciation | /mɪˈnɜːrvə/[1] |
| Named after | Minerva |
| 1949 QN2, A902 DA | |
| Minor planet category | Main belt |
| Adjectives | Minervian, Minervean /mɪˈnɜːrviən/ |
| Orbital characteristics[2] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 146.14 yr (53379 d) |
| |{{{apsis}}}|helion}} | 3.1429 astronomical unit|AU (470.17 Gm) |
| |{{{apsis}}}|helion}} | 2.3711 AU (354.71 Gm) |
| 2.7570 AU (412.44 Gm) | |
| Eccentricity | 0.13998 |
| Orbital period | 4.58 yr (1672.0 d) |
| Average Orbital speed | ~17.86 km/s |
| Mean anomaly | 262.022° |
| Mean motion | 0° 12m 55.116s / day |
| Inclination | 8.56143° |
| Longitude of ascending node | 4.06265° |
| 274.543° | |
| Physical characteristics | |
| Mean diameter | 154.155±1.298 km (IRAS)[2] 156 km[3] |
| Mass | 3.8×1018 kg (calculated)[lower-alpha 1] |
| Mean density | 1.9 g/cm3[3] |
Equatorial surface gravity | 4.139 cm/s2 (0.004221 g)[4] |
Equatorial escape velocity | 81 m/s[4] |
| Rotation period | 5.982 h (0.2493 d)[2] |
| Geometric albedo | 0.056±0.008[2] |
| C[2] G?[3] | |
| Absolute magnitude (H) | 7.91[2] |
93 Minerva is a large triple main-belt asteroid. It is a C-type asteroid, meaning that it has a dark surface and possibly a primitive carbonaceous composition. It was discovered by J. C. Watson on 24 August 1867, and named after Minerva, the Roman equivalent of Athena, goddess of wisdom. An occultation of a star by Minerva was observed in France, Spain and the United States on 22 November 1982. An occultation diameter of ~170 km was measured from the observations. Since then two more occultations have been observed, which give an estimated mean diameter of ~150 km.[5][6]
Satellites
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On 16 August 2009, at 13:36 UT, the Keck Observatory's adaptive optics system revealed that the asteroid 93 Minerva possesses 2 small moons.[7] They are 4 and 3 km in diameter and the projected separations from Minerva correspond to 630 km (8.8 x Rprimary) and 380 km (5.2 x Rprimary) respectively.[7] They have been named Aegis[8] (/ˈiːdʒɪs/)[9] and Gorgoneion[8] (/ˌɡɔːrɡəˈnaɪən/).[10]
Notes
- ↑ Using a spherical radius of 78 km; volume of a sphere * density of 1.9 g/cm3 yields a mass (m=d*v) of 3.78E+18 kg
References
- ↑ Noah Webster (1884) A Practical Dictionary of the English Language
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 "JPL Small-Body Database Browser: 93 Minerva". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=93.
- ↑ 3.0 3.1 3.2 Franck Marchis (7 October 2011). "Is the triple Asteroid Minerva a baby-Ceres?". NASA blog (Cosmic Diary). http://cosmicdiary.org/fmarchis/2011/10/07/the-secrets-of-asteroid-minerva-and-its-two-moons/.
- ↑ 4.0 4.1 "HEC:Exoplanets Calculator/Planet Density, Surface Gravity, and Escape Velocity". Planetary Habitability Laboratory. University of Puerto Rico at Arecibo. http://phl.upr.edu/projects/habitable-exoplanets-catalog/calculators.
- ↑ Millis, R.L; Wasserman, L.H; Bowell, E; Franz, O.G; Nye, R; Osborn, W; Klemola, A (1985), "The occultation of AG+29°398 by 93 Minerva", Icarus 61 (1): 124–131, doi:10.1016/0019-1035(85)90159-9, Bibcode: 1985Icar...61..124M
- ↑ "Observed minor planet occultation events". astro.cz. 26 July 2005. http://mpocc.astro.cz/world/mpocc1.txt.
- ↑ 7.0 7.1 Franck Marchis (2009-08-21). "The discovery of a new triple asteroid, (93) Minerva". Cosmic Diary Blog. http://cosmicdiary.org/fmarchis/2009/08/21/the-discovery-of-a-new-triple-asteroid-93-minerva/.
- ↑ 8.0 8.1 Franck Marchis (2013-12-26). "Asteroid Minerva finds its magical weapons in the sky". The Planetary Society. https://www.planetary.org/articles/20131224-asteroid-minerva-finds-its-magical-weapons-in-the-sky.
- ↑ "aegis". aegis. Oxford University Press. http://www.lexico.com/definition/aegis.
- ↑ "gorgoneion". gorgoneion. Oxford University Press. http://www.lexico.com/definition/gorgoneion.
External links
- 93 Minerva at AstDyS-2, Asteroids—Dynamic Site
- 93 Minerva at the JPL Small-Body Database
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