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Monday 30 January 2012

20th Largest Asteroid, 375 Ursula

375 Ursula is a large main belt asteroid and is the 20th largest asteroid currently known.

Discovery

Ursula was discovered by Auguste Honoré Charlois on September 18, 1893, in Nice.

Naming

Any reference of its name to a person or an occurrence is unknown.

Stats

Diameter (mean): 216 km
Aphelion: 3.46 AU
Perihelion: 2.79 AU
Semi-major axis: 3.123 AU
Orbital Period: 5.52 years
Rotation period: 16.83 hrs
Date discovered: 1893.9.18
Class: C
Type: Main-belt Asteroid
(data from JPL Small-Body Database)

Star Occultation

A value of 216 +/- 10 km for the mean diameter of Ursula is given, based on photometric measurements and observations of the occultation of AG + 39 deg 303, a K-type star of visual magnitude 8.8, by 375 Ursula on November 15, 1982.

From the occultation diameter and the absolute visual magnitudes presented, the visual geometric albedo of Ursula is determined to be 0.032, similar to the value typical of C-type asteroids.

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