11351 Leucus is a mid-sized
Jupiter trojan
The Jupiter trojans, commonly called trojan asteroids or simply trojans, are a large group of asteroids that share the planet Jupiter's orbit around the Sun. Relative to Jupiter, each trojan librates around one of Jupiter's stable Lagrange poin ...
from the
Greek camp
This is a list of Jupiter trojans that lie in the Greek camp, an elongated curved region around the leading Lagrangian point (), 60 ° ahead of Jupiter in its orbit.
All the asteroids at Jupiter's point have names corresponding to participants ...
, approximately in diameter. It is a target of the
''Lucy'' mission, scheduled for a fly by in April 2028.
The assumed
D-type asteroid
D-type asteroids have a very low albedo and a featureless reddish Asteroid spectral types, spectrum. It has been suggested that they have a composition of organic-rich silicates, carbon and anhydrous silicates, possibly with water ice in their inte ...
is an exceptionally
slow rotator with 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 466 hours.
It was discovered on 12 October 1997 by the
Beijing Schmidt CCD Asteroid Program
The Beijing Schmidt CCD Asteroid Program (SCAP) was an astronomical survey to search for near-Earth objects. It was conducted during the 1990s, at the Xinglong Station in Xinglong County, Chengde, Hebei province, China and resulted in the disco ...
(SCAP) at
Xinglong Station in the Chinese province of Hebei, and later named after the Achaean warrior
Leucus In Greek mythology, the name Leucus or Leukos (Ancient Greek: Λεῦκος "white") may refer to:
*Leucus, son of the bronze giant Talos of Crete and foster son of King Idomeneus. Following the advice of Nauplius, he seduced Meda, wife of Idomene ...
from Greek mythology.
Orbit and classification
''Leucus'' is a dark Jovian
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.
...
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 leading
Greek camp
This is a list of Jupiter trojans that lie in the Greek camp, an elongated curved region around the leading Lagrangian point (), 60 ° ahead of Jupiter in its orbit.
All the asteroids at Jupiter's point have names corresponding to participants ...
at Jupiter's
Lagrangian point
In celestial mechanics, the Lagrange points (; also Lagrangian points or libration points) are points of equilibrium for small-mass objects under the influence of two massive orbiting bodies. Mathematically, this involves the solution of th ...
, 60
° ahead of its orbit . It is also a non-
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 ...
asteroid in the
Jovian background population.
It orbits the Sun at a distance of 5.0–5.6
AU once every 12 years and 2 months (4,440 days;
semi-major axis
In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the long ...
of 5.29 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-center, in geometry
* Eccentricity (graph theory) of a v ...
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 Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...
of 12
° 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 again ...
.
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
In astronomy, precovery (short for pre-discovery recovery) is the process of finding the image of an object in images or photographic plates predating its discovery, typically for the purpose of calculating a more accurate orbit. This happens mos ...
taken at the
Siding Spring Observatory
Siding Spring Observatory near Coonabarabran, New South Wales, Australia, part of the Research School of Astronomy & Astrophysics (RSAA) at the Australian National University (ANU), incorporates the Anglo-Australian Telescope along with a coll ...
in July 1982, more than 15 years prior to its official discovery observation at Xinglong.
''Lucy'' mission target
''Leucus'' is planned to be visited by the
''Lucy'' spacecraft which will launch in 2021. The fly by is scheduled for 18 April 2028, and will approach the asteroid to a distance of 1000 kilometers at a velocity of 5.9 kilometers per second.
Physical characteristics
''Leucus'' is an assumed
D-type asteroid
D-type asteroids have a very low albedo and a featureless reddish Asteroid spectral types, spectrum. It has been suggested that they have a composition of organic-rich silicates, carbon and anhydrous silicates, possibly with water ice in their inte ...
,
which is the dominant
spectral type
In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...
among the Jovian asteroids, with the remainder being mostly carbonaceous
C-type 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-type ...
s.
Slow rotator
During spring 2013, 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 frequ ...
of ''Leucus'' was obtained from
photometric observations made by astronomers
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 natur ...
and Daniel Coley at the Center for Solar System Studies (CS3), California, using a 0.35/0.4-meter
Schmidt-Cassegrain telescope. The lightcurve showed an exceptionally slow
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 513.7 hours with a brightness variation of 0.53 in
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 ...
(). No evidence of a non-principal axis rotation (NPAR) was found.
It is one of the
slowest rotators known to exist.
In preparation for the planned visit by the ''
Lucy
Lucy is an English feminine given name derived from the Latin masculine given name Lucius with the meaning ''as of light'' (''born at dawn or daylight'', maybe also ''shiny'', or ''of light complexion''). Alternative spellings are Luci, Luce, Luci ...
'' spacecraft, ''Leucus'' was once again observed by astronomers
Marc Buie
Marc William Buie (; born 1958) is an American astronomer and prolific discoverer of minor planets who works at the Southwest Research Institute in Boulder, Colorado in the Space Science Department. Formerly he worked at the Lowell Observatory ...
at
SwRI and
Stefano Mottola
This is a list of minor-planet discoverers credited by the Minor Planet Center with the discovery of one or several minor planets (such as near-Earth and main-belt asteroids, Jupiter trojans and distant objects). , the discovery of 612,011 numb ...
at
DLR in 2016. The obtained bimodal lightcurve gave a somewhat shorter period of 440 hours and an amplitude of 0.7 magnitude.
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite
IRAS
The Infrared Astronomical Satellite (Dutch: ''Infrarood Astronomische Satelliet'') (IRAS) was the first space telescope to perform a survey of the entire night sky at infrared wavelengths. Launched on 25 January 1983, its mission lasted ten mo ...
, and 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 2011, ...
with its subsequent
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 2011, ...
mission, ''Leucus'' has a low
albedo
Albedo (; ) is the measure of the diffuse reflection of sunlight, 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 ...
of 0.06 and 0.08, with a diameter of 42.1 and 34.2 kilometers, respectively.
The ''
Collaborative Asteroid Lightcurve Link'' derives a lower albedo of 0.05 and a diameter of 42.1 kilometers, in accordance with the result obtained by IRAS.
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 ''minor ...
was named from
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 ...
, after the Achaean warrior
Leucus In Greek mythology, the name Leucus or Leukos (Ancient Greek: Λεῦκος "white") may refer to:
*Leucus, son of the bronze giant Talos of Crete and foster son of King Idomeneus. Following the advice of Nauplius, he seduced Meda, wife of Idomene ...
in Homer's ''Iliad''. He was a companion of
Odysseus
Odysseus ( ; grc-gre, Ὀδυσσεύς, Ὀδυσεύς, OdysseúsOdyseús, ), also known by the Latin variant Ulysses ( , ; lat, UlyssesUlixes), is a legendary Greek king of Ithaca and the hero of Homer's epic poem the ''Odyssey''. Odysse ...
.
Leucus was killed during the
Trojan War
In Greek mythology, the Trojan War was waged against the city of Troy by the Achaeans (Greeks) after Paris of Troy took Helen from her husband Menelaus, king of Sparta. The war is one of the most important events in Greek mythology and has ...
by
Antiphus
In Greek mythology, Antiphus or Ántiphos ( /ˈæntəfəs/; Ancient Greek: Ἄντιφος) is a name attributed to multiple individuals:
*Antiphus, a Phthian prince as the son of King Myrmidon and Peisidice, and brother of Actor. He may be the ...
, one of the fifty sons of King
Priam
In Greek mythology, Priam (; grc-gre, Πρίαμος, ) was the legendary and last king of Troy during the Trojan War. He was the son of Laomedon. His many children included notable characters such as Hector, Paris, and Cassandra.
Etymology
Mo ...
of Troy.
Homer
Homer (; grc, Ὅμηρος , ''Hómēros'') (born ) was a Greek poet who is credited as the author of the ''Iliad'' and the ''Odyssey'', two epic poems that are foundational works of ancient Greek literature. Homer is considered one of the ...
, ''Iliad
The ''Iliad'' (; grc, Ἰλιάς, Iliás, ; "a poem about Ilium") is one of two major ancient Greek epic poems attributed to Homer. It is one of the oldest extant works of literature still widely read by modern audiences. As with the ''Odysse ...
'', 4. 491 The approved naming citation was published by the
Minor Planet Center
The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory.
Function
...
on 22 February 2016 ().
Notes
References
External links
Asteroid Lightcurve Database (LCDB) query form
)
Dictionary of Minor Planet Names Google books
– Minor Planet Center
Asteroid 11351 Leucusat the Small Bodies Data Ferret
*
*
{{DEFAULTSORT:011351
Jupiter trojans (Greek camp)
Discoveries by SCAP
Leucus In Greek mythology, the name Leucus or Leukos (Ancient Greek: Λεῦκος "white") may refer to:
*Leucus, son of the bronze giant Talos of Crete and foster son of King Idomeneus. Following the advice of Nauplius, he seduced Meda, wife of Idomene ...
Slow rotating minor planets
Minor planets to be visited by spacecraft
Objects observed by stellar occultation
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