Niobewith the stress on the first syllable (

minor planet designation A formal minor-planet designation is, in its final form, a number–name combination given to a minor planet (asteroid, centaur, trans-Neptunian object and dwarf planet but not comet). Such designation always features a leading number (catalog or ...

: 71 Niobe) is a stony Gallia

asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

and relatively slow rotator from the central regions of the

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called ...

, approximately in diameter. It was discovered by the German astronomer

Robert Luther Karl Theodor Robert Luther (April 16, 1822, Świdnica – February 15, 1900 Düsseldorf), normally published as Robert Luther, was a German astronomer. While working at the Bilk Observatory in Düsseldorf, Germany, he searched for asteroids and ...

on 13 August 1861, and named after

Niobe In Greek mythology, Niobe (; grc-gre, Νιόβη ) was a daughter of Tantalus and of either Dione, the most frequently cited, or of Eurythemista or Euryanassa, the wife of Amphion and the sister of Pelops and Broteas. Her father was the ru ...

, a character in

Greek mythology A major branch of classical mythology, Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the Cosmogony, origin and Cosmology#Metaphysical co ...

. In 1861, the brightness of this asteroid was shown to vary by astronomer

Friedrich Tietjen Friedrich Tietjen (1832 in Westerstede, Oldenburg – 1895 in Berlin) was a German astronomer. He was director of the ''Astronomisches Rechen-Institut'' (ARI) from 1874 until his death in 1895. The Minor Planet Center credits him with the di ...

Description

''Niobe'' is a member of the Gallia family (), a small

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

of nearly 200 known stony asteroids. In 2006, it was examined by

radar Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, w ...

using the

Arecibo Observatory The Arecibo Observatory, also known as the National Astronomy and Ionosphere Center (NAIC) and formerly known as the Arecibo Ionosphere Observatory, is an observatory in Barrio Esperanza, Arecibo, Puerto Rico owned by the US National Science F ...

radio telescope in

Puerto Rico Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and Unincorporated ...

. This was supplemented by optical observations intended to build a

lightcurve In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequ ...

. The resulting estimated rotation period of 35.6 hours, or 1.48 Earth days, superseded an earlier estimate of the rotation period as 14.3 hours. The radar data produced an estimate of a maximum equatorial diameter of 94 km, which is consistent with earlier estimates based upon infrared data if the shape is assumed to be slightly elongated. The rotation period was further refined to during observations through 2010. Six stellar occultations of this asteroid between 2004 and 2007 produced chords ranging from 13 to 72 km (8–45 mi), which are statistically consistent with the published maximum diameter estimates.

Notes

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Observatoire de Genève, Raoul Behrend

– Minor Planet Center * * {{DEFAULTSORT:000071 Gallia asteroids

S-type asteroids (Tholen) Xe-type asteroids (SMASS) 18610813