(15094) Polymele

Asteroid (15094) Polymele
Properties of the orbit ( animation )
Orbit type	Jupiter Trojan (L 4 )
Major semi-axis	5.164  AU
eccentricity	0.0944
Perihelion - aphelion	4.677 AU - 5.652 AU
Inclination of the orbit plane	12.99 °
Length of the ascending node	50.329 °
Argument of the periapsis	4.885 °
Time of passage of the perihelion	September 14, 2021
Sidereal period	11 a 270 d
Physical Properties
Medium diameter	21.075 km
Albedo	0.091
Rotation period	(4) h
Absolute brightness	11.7 mag
Spectral class	P
history
Explorer	Catalina Sky Survey
Date of discovery	November 17, 1999
Another name	1999 WB 2 , 1997 WR 57
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items.

(15094) Polymele is an asteroid belonging to the group of Trojans . It is used to describe asteroids that move on the orbit of Jupiter around the sun.

Discovery and naming

The asteroid was discovered in the Santa Catalina Mountains as part of NASA's Catalina Sky Survey program , which was launched in 1998 to search for potentially dangerous near-Earth asteroids . The program will be conducted at the Mount Lemmon Observatory near Tucson , Arizona ( USA ) and the Siding Spring Observatory near Coonabarabran in New South Wales , Australia . The team of astronomers involved consists of Stephen M. Larson (lead), Ed Beshore, Richard E. Hill, Richard A. Kowalski, Alex R. Gibbs, Andrea Boattini and Albert D. Grauer (USA) as well as Robert H. McNaught , Gordon J. Garradd and Donna Burton (Australia).

Polymele is named according to Gaius Iulius Hyginus (* around 60 BC; † after 4 AD) after the wife of Menoitios from Greek mythology , with whom she fathered the warrior Patroclus , and was the daughter of the Myrmidon king Peleus .
According to another version, Polymele was the daughter of Aktor von Phthia and - even before Thetis - the wife of Peleus, to whom she gave birth to Polydora .

Track properties

Polymele is located near Jupiter's Lagrange point L ₄ and thus belongs to the Greek group of Trojans who hurry ahead of the planet. Its orbit runs between 4.677 ( perihelion ) and 5.652 ( aphelion ) astronomical units and is just under 13.0 ° inclined to the ecliptic . The orbital eccentricity is 0.094.

Observations of the asteroid's light curve indicated a period of rotation of approximately 4 hours.

Physical Properties

It is currently assumed to be around 21 km in diameter. This value is based on an assumed reflectivity of 9.1% and an absolute brightness of 11.7 mag.

Polymele is believed to be a collision fragment. The asteroid belongs to the class of the P-type asteroids and should therefore - like most Trojans - have a reddish surface.

exploration

After its discovery, Polymele could be dated back to 1951 on photos and thus calculated its orbit. Since then, the asteroid has been observed through various telescopes, a total of 581 times. (As of February 2017)

On January 4, 2017, NASA decided to deploy the Lucy space probe , which is scheduled to launch in October 2021 and reach Polymele in September 2027. In addition to Polymele, the L ₄ Trojans (3548) Eurybates , (11351) Leucus and (21900) Orus will also be investigated between 2027 and 2028 . The probe will then swing-by the Earth to reach the L ₅ double Trojans (617) Patroclus and Menoetius in March 2033. The objective of the mission is a more precise determination of the shape and size as well as the rotation and the spectroscopic properties of the asteroids mentioned.

See also

• List of asteroids
• List of Jupiter Trojans

Individual evidence

1. ↑ Ground-based characterization of Leucus and Polymele, two fly-by targets of the Lucy Discovery mission , October 2016, bibcode : 2016DPS .... 4820806B (English)
2. ↑ (15094) Polymele in the Small-Body Database of the Jet Propulsion Laboratory (English).