19 Fortuna

Infobox Planet | discovery=yes | physical_characteristics = yes | bgcolour=#FFFFC0 | name=19 Fortuna
discoverer=John Russell Hind
discovered=August 22, 1852
alt_names=A902 UG
mp_category=Main belt
epoch=October 22, 2004 (JD 2453300.5)
semimajor=365.235 Gm (2.441 AU)
perihelion=307.028 Gm (2.052 AU)
aphelion=423.443 Gm (2.831 AU)
eccentricity=0.159
period=1393.378 d (3.81 a)
inclination=1.573°
asc_node=211.379°
arg_peri=182.091°
mean_anomaly=268.398°
avg_speed=18.94 km/s
dimensions=225.0 kmcite journal
last=Storrs |first=Alex
coauthors=Weiss, B.; Zellner, B.; et.al.
title=Imaging Observations of Asteroids with Hubble Space Telescope
journal=Icarus
volume=137 |pages=260–268 |year=1998
url=http://web.media.mit.edu/~win/hstpub.pdf
accessdate=2005-01-15
doi=10.1006/icar.1999.6047 ]
mass=~1.2e|19 kg
density=2.0? g/cm³
surface_grav=~0.0629 m/s²
escape_velocity=~0.1190 km/s
rotation=0.3101 d (7.445 h)
spectral_type=G
magnitude = 8.88 to 12.95
abs_magnitude=7.13
albedo=0.037
angular_size = 0.25" to 0.072"
single_temperature=~180 K

19 Fortuna (pronEng|fɔrˈtjuːnə, _la. 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. [cite web|url=http://web.mit.edu/bpweiss/www/StorrsWeiss2005AsteroidsHSTIcarus.pdf |title= A closer look at main belt asteroids 1: WF/PC images (Icarus 173) |accessdate=2007-09-23]

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.

References

External links

* [http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=19;orb=1 Orbital simulation] from JPL (Java) / [http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=19 Ephemeris]