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19 Fortuna

Discovery
Discovered by	John Russell Hind
Discovery date	22 August 1852
Designations
MPC designation	(19) Fortuna
Pronunciation	/fɔːrˈtjuːnə/
Named after	Fortūna
Alternative designations	A902 UG
Minor planet category	Main belt
Adjectives	Fortunian /fɔːrˈtjuːniən/
Symbol	(historical)
Orbital characteristics
Epoch 17.0 October 2024 (JD 2460600.5)
Aphelion	2.831 AU (423.443 Gm)
Perihelion	2.052 AU (307.028 Gm)
Semi-major axis	2.441 AU (365.235 Gm)
Eccentricity	0.159
Orbital period (sidereal)	3.81 a (1393.378 d)
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°
Earth MOID	1.06316 AU
Jupiter MOID	2.60305 AU
TJupiter	3.483
Physical characteristics
Dimensions	(225 × 205 × 195) ± 12 km (242 × 203 × 192) ± 10 km
Mean diameter	211±2 km 225 km
Flattening	0.21
Mass	(8.8±1.4)×10 kg 12.7×10 kg
Mean density	1.80±0.29 g/cm 2.70±0.48 g/cm
Equatorial surface gravity	~0.0629 m/s²
Equatorial escape velocity	~0.1190 km/s
Synodic rotation period	7.4432 h (0.3101 d) 7.443224±0.000001 h
Axial tilt	29°
Pole ecliptic latitude	60°±3°
Pole ecliptic longitude	103°±3°
Geometric albedo	0.056 0.037
Temperature	~180 K
Spectral type	G
Apparent magnitude	8.88 to 12.95
Absolute magnitude (H)	7.49 7.13
Angular diameter	0.25" to 0.072"

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.

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. The spectra of the asteroid displays evidence of aqueous alteration.

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.

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 𜻌 ().

Fortuna has been perturbed by the 80 km 135 Hertha and was initially estimated by Baer to have a mass of 1.08×10 kg. A more recent estimate by Baer suggests it has a mass of 1.27×10 kg.

On 21 December 2012, Fortuna (~200 km) harmlessly passed within 6.5 Gm of asteroid 687 Tinette.

Notes

1. Flattening derived from the maximum aspect ratio (c/a): ${\displaystyle f=1-{\frac {c}{a}}}$, where (c/a) = 0.79±0.05.

References

1. Noah Webster (1884) A Practical Dictionary of the English Language
2. ^ "JPL Small-Body Database Browser: 19 Fortuna" (2024-11-14 last obs). Retrieved 21 December 2024.
3. ^ Jim Baer (2008). "Recent Asteroid Mass Determinations". Personal Website. Archived from the original on 21 October 2013. Retrieved 27 November 2008.
4. ^ P. Vernazza et al. (2021) VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis. Astronomy & Astrophysics 54, A56
5. 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.
6. ^ 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.
7. "AstDys (19) Fortuna Ephemerides". Department of Mathematics, University of Pisa, Italy. Retrieved 27 June 2010.
8. 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.
9. 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.
10. "Radar-Detected Asteroids and Comets". NASA/JPL Asteroid Radar Research. Retrieved 30 October 2011.
11. Bala, Gavin Jared; Miller, Kirk (18 September 2023). "Unicode request for historical asteroid symbols" (PDF). unicode.org. Unicode. Retrieved 26 September 2023.
12. Unicode. "Proposed New Characters: The Pipeline". unicode.org. The Unicode Consortium. Retrieved 6 November 2023.
13. Generated with Solex 10 Archived 20 December 2008 at the Wayback Machine by Aldo Vitagliano

External links

• 19 Fortuna at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 19 Fortuna at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

• Minor planet object articles (numbered)
• Background asteroids
• Discoveries by John Russell Hind
• Named minor planets
• G-type asteroids (Tholen)
• Ch-type asteroids (SMASS)
• Astronomical objects discovered in 1852