645 Agrippina, provisional designation 1907 AG, is a stony

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. ...

from the outer region of the asteroid belt, roughly 30 kilometers in diameter. It was discovered by American astronomer reverend Joel Metcalf at Taunton, Massachusetts, USA, on 13 September 1907. The S-type asteroid orbits the Sun at a distance of 2.7–3.7 AU once every 5 years and 9 months (2,103 days). Its orbit shows an eccentricity of 0.15 and is tilted by 7 degrees to the plane of the ecliptic. A photometric light-curve analysis from the 1980s and a provisional observation in 2004 rendered a

rotation period The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the ...

of 32.6 and 34.4 hours, respectively. According to the surveys carried out by the Infrared Astronomical Satellite, IRAS, the Japanese Akari satellite, and the U.S. Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the asteroid has a dissimilar albedo in the range of 0.14 to 0.23, which leads to a varying estimate for its diameter from 28 to 36 kilometers. The ''Collaborative Asteroid Lightcurve Link'' publishes an albedo of 0.23 from an alternative result of the Supplemental IRAS Minor Planet Survey (SIMPS) and derives a slightly lower diameter of 27.9 kilometers. The minor planet was named for two women of

ancient Roman In modern historiography, ancient Rome refers to Roman civilisation from the founding of the city of Rome in the 8th century BC to the collapse of the Western Roman Empire in the 5th century AD. It encompasses the Roman Kingdom (753–509 BC ...

history. Agrippina the Elder (14 BCE – 33) was the daughter of the Roman statesman

Marcus Vipsanius Agrippa Marcus Vipsanius Agrippa (; BC – 12 BC) was a Roman general, statesman, and architect who was a close friend, son-in-law, and lieutenant to the Roman emperor Augustus. He was responsible for the construction of some of the most notable buildi ...

, the wife of

Germanicus Germanicus Julius Caesar (24 May 15 BC – 10 October AD 19) was an ancient Roman general, known for his campaigns in Germania. The son of Nero Claudius Drusus and Antonia the Younger, Germanicus was born into an influential branch of the Patric ...

and the mother of the Emperor

Caligula Gaius Julius Caesar Augustus Germanicus (31 August 12 – 24 January 41), better known by his nickname Caligula (), was the third Roman emperor, ruling from 37 until his assassination in 41. He was the son of the popular Roman general Germanicu ...

. Her daughter,

Agrippina the Younger Julia Agrippina (6 November AD 15 – 23 March AD 59), also referred to as Agrippina the Younger, was Roman empress from 49 to 54 AD, the fourth wife and niece of Emperor Claudius. Agrippina was one of the most prominent women in the Julio-Claud ...

(15–59 AD) was the mother of Emperor Nero. The naming might be influenced by the two letters of the provisional designation ''1907 AG''. In the ''Dictionary of Minor Planet Names'', Lutz Schmadel supposes that the name originated from a list of female names from mythology and history, compiled by the Astronomisches Rechen-Institut (ARI) in 1913. The ARI then sent this list to a number of astronomers with the request to name their discoveries in order to avoid confusion, as the number of unnamed minor planet up to number 700 had grown significantly at the time.

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:000645 Background asteroids

Agrippina Agrippina is an ancient Roman cognomen and a feminine given name. People with either the cognomen or the given name include: Cognomen Relatives of the Roman general Marcus Vipsanius Agrippa: * Vipsania Agrippina (36 BC–20 AD), first wife of th ...

S-type asteroids (Tholen) 19070913