19 Fortuna 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.
 | |
| Discovery | |
|---|---|
| Discovered by | John Russell Hind |
| Discovery date | 22 August 1852 |
| Designations | |
| (19) Fortuna | |
| Pronunciation | /fɔːrˈtjuːnə/[1] |
Named after | Fortūna |
| A902 UG | |
| Main belt | |
| Adjectives | Fortunian /fɔːrˈtjuːniən/ |
| Symbol | .svg){kind=small} (historical) |
| Orbital characteristics[2] | |
| Epoch 22 October 2004 (JD 2453300.5) | |
| Aphelion | 2.831 AU (423.443 Gm) |
| Perihelion | 2.052 AU (307.028 Gm) |
| 2.441 AU (365.235 Gm) | |
| Eccentricity | 0.159 |
| 3.81 a (1393.378 d) | |
Average orbital speed | 18.94 km/s |
| 268.398° | |
| Inclination | 1.573° |
| 211.379° | |
| 182.091° | |
| Physical characteristics | |
| Dimensions | (225×205×195)±12 km[3] |
| 211±2 km[4] 225 km[5][6] | |
| Flattening | 0.21[a] |
| Mass | (8.8±1.4)×1018 kg[4] 12.7×1018 kg[3] |
Mean density | 1.80±0.29 g/cm3[4] 2.70±0.48 g/cm3[3] |
Equatorial surface gravity | ~0.0629 m/s² |
Equatorial escape velocity | ~0.1190 km/s |
| 0.3101 d (7.4432 h)[2] | |
| 0.056[4] 0.037[2] | |
| Temperature | ~180 K |
| G[2] | |
| 8.88[7] to 12.95 | |
| 7.13[2] | |
| 0.25" to 0.072" | |
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.[8] The spectra of the asteroid displays evidence of aqueous alteration.[9]
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. Fortuna has been studied by radar.[10]
It was discovered by J. R. Hind on 22 August 1852, and named after Fortuna, the Roman goddess of luck. Its historical symbol was a star over Fortune's wheel; it is in the pipeline for Unicode 17.0 as U+1CECC (.svg){kind=small}
).[11][12]
Fortuna has been perturbed by the 80 km 135 Hertha and was initially estimated by Baer to have a mass of 1.08×1019 kg.[6] A more recent estimate by Baer suggests it has a mass of 1.27×1019 kg.[3]
On 21 December 2012, Fortuna (~200 km) harmlessly passed within 6.5 Gm of asteroid 687 Tinette.[13]
Notes
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References
edit- ^ Noah Webster (1884) A Practical Dictionary of the English Language
- ^ a b c d e "JPL Small-Body Database Browser: 19 Fortuna" (2008-08-21 last obs). Retrieved 11 November 2008.
- ^ a b c d Jim Baer (2008). "Recent Asteroid Mass Determinations". Personal Website. Archived from the original on 21 October 2013. Retrieved 27 November 2008.
- ^ 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
- ^ Storrs, Alex; Weiss, B.; Zellner, B.; et al. (1998). "Imaging Observations of Asteroids with Hubble Space Telescope" (PDF). Icarus. 137 (2): 260–268. Bibcode:1999Icar..137..260S. doi:10.1006/icar.1999.6047. Archived from the original (PDF) on February 25, 2012. Retrieved January 15, 2005.
- ^ a b Baer, James; Steven R. Chesley (2008). "Astrometric masses of 21 asteroids, and an integrated asteroid ephemeris". Celestial Mechanics and Dynamical Astronomy. 100 (2008). Springer Science+Business Media B.V. 2007: 27–42. Bibcode:2008CeMDA.100...27B. doi:10.1007/s10569-007-9103-8.
- ^ "AstDys (19) Fortuna Ephemerides". Department of Mathematics, University of Pisa, Italy. Retrieved 27 June 2010.
- ^ Storrs, Alex; Dunne; Conan; Mugnier; et al. (2005). "A closer look at main belt asteroids 1: WF/PC images" (PDF). Icarus. 173 (2): 409–416. Bibcode:2005Icar..173..409S. doi:10.1016/j.icarus.2004.08.007. Archived from the original (PDF) on 18 April 2007. Retrieved 23 September 2007.
- ^ Fornasier, S.; et al. (February 1999), "Spectroscopic comparison of aqueous altered asteroids with CM2 carbonaceous chondrite meteorites", Astronomy and Astrophysics Supplement, 135: 65–73, Bibcode:1999A&AS..135...65F, doi:10.1051/aas:1999161.
- ^ "Radar-Detected Asteroids and Comets". NASA/JPL Asteroid Radar Research. Retrieved 30 October 2011.
- ^ 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.
- ^ Generated with Solex 10 Archived 20 December 2008 at the Wayback Machine by Aldo Vitagliano
External links
edit- 19 Fortuna at AstDyS-2, Asteroids—Dynamic Site
- 19 Fortuna at the JPL Small-Body Database
