9023 Mnesthus is a large Jupiter trojan from the

Trojan camp This is a list of Jupiter trojans that lie in the Trojan camp, an elongated curved region around the trailing Lagrangian point, 60° behind Jupiter. All the asteroids at the trailing point have names corresponding to participants on the Troj ...

, approximately in diameter. It was discovered on 10 September 1988, by American astronomer couple Carolyn and

Eugene Shoemaker Eugene Merle Shoemaker (April 28, 1928 – July 18, 1997) was an American geologist. He co-discovered Comet Shoemaker–Levy 9 with his wife Carolyn S. Shoemaker and David H. Levy. This comet hit Jupiter in July 1994: the impact was televise ...

at the Palomar Observatory in California. The dark Jovian asteroid belongs to the 100 largest Jupiter trojans and has a longer-than-average rotation period of 30.7 hours. It was named after the Trojan

Mnestheus Mnestheus is a character from Roman mythology, found in Virgil's ''Aeneid''. He is described by Virgil as the ancestral hero of the Memmii and "Of the house of Assaracus". One of a handful of vaguely defined lieutenants under Aeneas, he appears to ...

, a companion of

Aeneas In Greco-Roman mythology, Aeneas (, ; from ) was a Trojan hero, the son of the Trojan prince Anchises and the Greek goddess Aphrodite (equivalent to the Roman Venus). His father was a first cousin of King Priam of Troy (both being grandsons ...

in Classical mythology.

Orbit and classification

''Mnesthus'' is a dark Jovian asteroid in a 1:1

orbital resonance In celestial mechanics, orbital resonance occurs when orbiting bodies exert regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers. Most commonly, this relationsh ...

with Jupiter. It is located in the trailering

at the Gas Giant's Lagrangian point, 60 ° behind its orbit . It is also a non-

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

asteroid of the Jovian background population. It orbits the Sun at a distance of 4.9–5.6 AU once every 11 years and 11 months (4,365 days; semi-major axis of 5.23 AU). Its orbit has an

eccentricity Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (g ...

of 0.06 and an

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

of 24 ° with respect to the

ecliptic The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic agains ...

. The body's

observation arc In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly use ...

begins with a precovery at Palomar in July 1950, more than 38 years prior to its official discovery observation.

Naming

This

minor planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''mino ...

was named from Greco-Roman mythology after the Trojan

, a companion and officer of

in Classical mythology. He is one of the wandering

Aeneads :''This is for the mythical allies of Aeneas. For the story written about them by Virgil, see Aeneid'' In Roman mythology, the Aeneads ( grc, Αἰνειάδαι) were the friends, family and companions of Aeneas, with whom they fled from Troy afte ...

who traveled to Italy after the downfall of Troy. At the funeral games for Aeneas' father, Anchises, he competes in both the sailing and the archery contests, winning second place in sailing. The official naming citation was published by the Minor Planet Center on 13 October 2000 ().

Physical characteristics

''Mnesthus'' is an assumed

C-type asteroid C-type (carbonaceous) asteroids are the most common variety, forming around 75% of known asteroids. They are volatile-rich and distinguished by a very low albedo because their composition includes a large amount of carbon, in addition to rocks ...

. Jovian asteroids are typically D-types, with the remainder being mostly carbonaceous C- and primitive

P-type asteroid P-type asteroids are asteroids that have low albedo and a featureless reddish spectrum. It has been suggested that they have a composition of organic rich silicates, carbon and anhydrous silicates, possibly with water ice in their interior. P-t ...

Rotation period

In August 2011, a rotational

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 freq ...

of ''Mnesthus'' was obtained from photometric observations by Daniel Coley and

Robert Stephens Sir Robert Graham Stephens (14 July 193112 November 1995) was a leading English actor in the early years of Britain's Royal National Theatre. He was one of the most respected actors of his generation and was at one time regarded as the natu ...

at the Center for Solar System Studies and GMARS , respectively. Lightcurve analysis gave a longer-than average rotation period of hours with a brightness amplitude of 0.23

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

().

Diameter and albedo

According to the surveys carried out by the

NEOWISE Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 201 ...

mission of NASA's

Wide-field Infrared Survey Explorer Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 201 ...

and the Japanese Akari satellite, ''Mnesthus'' measures 49.15 and 60.80 kilometers in diameter and its surface has an

albedo Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that refl ...

of 0.073 and 0.033, respectively. The ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 50.77 kilometers based on an

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it ...

of 10.2.

Orbit and classification

Naming

Physical characteristics

Rotation period

Diameter and albedo

Notes

References

External links