19 Fortuna

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19 Fortuna
Discovered by John Russell Hind
Discovery time August 22, 1852
Other names A902 UG
Group Main belt
Reference date October 22, 2004 (JD 2453300.5)
Longest distance from the Sun 423.443 Gm (2.831 AU)
Shortest distance from the Sun 307.028 Gm (2.052 AU)
Longest distance from the center of its orbital path
("semi-major axis")
365.235 Gm (2.441 AU)
How egg-shaped its orbit is
How long it takes to complete an orbit 1393.378 d (3.81 a)
Average speed 18.94 km/s
Mean anomaly 268.398°
Angle above the reference plane
Longitude of where it comes up through the reference plane 211.379°
Angle between its shortest distance from what it orbits around and where it comes up through the reference plane
("argument of periapsis")
Size and Other Qualities
Measures 225.0 km[1]
Mass ~1.2×1019 kg
Average density 2.0? g/cm³
Gravity at its surface ~0.0629 m/s²
Slowest speed able to escape into space
("escape velocity")
~0.1190 km/s
How long it takes to turn around one time 0.3101 d (7.445 h)
How much light it reflects 0.037
Avg. surface temp. ~180 K
Light-band group
("spectral type")
Seeming brightness
("apparent magnitude")
8.88 to 12.95
True brightness
("absolute magnitude")
Seeming size
("angular diameter")
0.25" to 0.072"

19 Fortuna is one of the biggest main belt asteroids. It is made up of stuff similar to 1 Ceres: a darkly colored surface that is heavily space weathered and made up 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 saw 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. Moons were searched for but none were detected.

Stellar occultations by Fortuna have been seen several times.

It was found by J. R. Hind on August 22, 1852 and named after Fortuna, the Roman goddess of luck.

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