19 Fortuna
From Wikipedia, the free encyclopedia
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Discovery
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| Discovered by | John Russell Hind |
| Discovery date | August 22, 1852 |
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Designations
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| Alternative names | A902 UG |
| Minor planet category |
Main belt |
| Epoch October 22, 2004 (JD 2453300.5) | |
| Aphelion | 423.443 Gm (2.831 AU) |
| Perihelion | 307.028 Gm (2.052 AU) |
| Semi-major axis | 365.235 Gm (2.441 AU) |
| Eccentricity | 0.159 |
| Orbital period | 1393.378 d (3.81 a) |
| Average orbital speed | 18.94 km/s |
| Mean anomaly | 268.398° |
| Inclination | 1.573° |
| Longitude of ascending node | 211.379° |
| Argument of perihelion | 182.091° |
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Physical characteristics
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| Dimensions | 225.0 km[1] |
| Mass | ~1.2×1019 kg |
| Mean density | 2.0? g/cm³ |
| Equatorial surface gravity | ~0.0629 m/s² |
| Escape velocity | ~0.1190 km/s |
| Rotation period | 0.3101 d (7.445 h) |
| Albedo | 0.037 |
| Temperature | ~180 K |
| Spectral type | G |
| Apparent magnitude | 8.88 to 12.95 |
| Absolute magnitude | 7.13 |
| Angular diameter | 0.25" to 0.072" |
19 Fortuna (pronounced /fɔrˈtjuːnə/, Latin: Fortūna) is one of the largest main belt asteroids. It has a composition similar to 1 Ceres: a darkly colored surface that is heavily space weathered with the composition of primitive organic compounds, including tholins.
Fortuna is 225 km in diameter and has one of the darkest known geometric albedos for an asteroid over 150 km in diameter. Its albedo has been measured at 0.028 and 0.037.[2]
The Hubble Space Telescope observed Fortuna in 1993. It was resolved with an apparent diameter of 0.20 arcseconds (4.5 pixels in the Planetary Camera) and its shape was found to be nearly spherical. Satellites were searched for but none were detected.
Stellar occultations by Fortuna have been observed several times.
It was discovered by J. R. Hind on August 22, 1852 and named after Fortuna, the Roman goddess of luck.
[edit] References
- ^ Storrs, Alex; Weiss, B.; Zellner, B.; et.al. (1998). "Imaging Observations of Asteroids with Hubble Space Telescope". Icarus 137: 260-268.
- ^ A closer look at main belt asteroids 1: WF/PC images (Icarus 173). Retrieved on 2007-09-23.
[edit] External links
- Orbital simulation from JPL (Java) / Ephemeris
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