4197 Morpheus, provisional designation , is a highly eccentric
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
near-Earth object
A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...
of the
Apollo group
Apollo Education Group, Inc. is an American corporation based in the South Phoenix area of Phoenix, Arizona, with an additional corporate office in Chicago, Illinois.
The company owns and operates several higher-learning institutions, including ...
, approximately 3 kilometers in diameter. It was discovered on 11 October 1982, by American astronomers
Eleanor Helin
Eleanor Francis "Glo" Helin (née Francis, 19 November 1932 – 25 January 2009) was an American astronomer. She was principal investigator of the Near-Earth Asteroid Tracking (NEAT) program of NASA's Jet Propulsion Laboratory. (Some sources gi ...
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
Palomar Observatory
Palomar Observatory is an astronomical research observatory in San Diego County, California, United States, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observat ...
in California, United States. The asteroid was later named for
Morpheus
Morpheus ('Fashioner', derived from the grc, μορφή meaning 'form, shape') is a god associated with sleep and dreams. In Ovid's ''Metamorphoses'' he is the son of Somnus and appears in dreams in human form. From the Middle Ages, the name b ...
from Greek mythology.
Orbit and classification
''Morpheus'' orbits the Sun at a distance of 0.5–4.1
AU once every 3 years and 6 months (1,271 days). 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 0.77 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 13
° 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 ...
.
Due to this elongated orbit, the asteroid is both, a
Mars-crosser
A Mars-crossing asteroid (MCA, also Mars-crosser, MC) is an asteroid whose orbit crosses that of Mars. Some Mars-crossers numbered below 100000 are listed here. They include the two numbered Mars trojans 5261 Eureka and .
Many databases, for i ...
and a
Venus-crosser
A Venus-crosser is an asteroid whose orbit crosses that of Venus. There are 2,809 .
It has a
minimum orbit intersection distance
Minimum orbit intersection distance (MOID) is a measure used in astronomy to assess potential close approaches and collision risks between astronomical objects. It is defined as the distance between the closest points of the osculating orbits of ...
with Earth of , which corresponds to 38.5
lunar distances.
A first
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 ...
was taken at the discovering observatory in 1954, extending 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 ...
by 28 years prior to its official discovery observation.
Physical characteristics
On the
SMASS taxonomic scheme, ''Morpheus'' is classified as a stony Sq sub-type, which transitions from the common
S-type to the rather rare
Q-type asteroid
Q-type asteroids are relatively uncommon inner-belt asteroids with a strong, broad 1 micrometre olivine and pyroxene feature, and a spectral slope that indicates the presence of metal. There are absorption features shortwards and longwards of 0. ...
s.
Diameter and albedo
In the 1990s,
Tom Gehrels
Anton M.J. "Tom" Gehrels (February 21, 1925 – July 11, 2011) was a Dutch–American astronomer, Professor of Planetary Sciences, and Astronomer at the University of Arizona, Tucson.
Biography
Youth and education
Gehrels was born at Haa ...
gave a first diameter estimate for ''Morpheus'' of 1.8 kilometers.
According to the survey 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 2011, ...
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 2011, ...
(WISE), it measures 3.043 kilometers in diameter and its surface has an
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 0.276.
In 2012, a revision of the published WISE-data by
Petr Pravec
Petr Pravec (born September 17, 1967) is a Czech astronomer and a discoverer of minor planets, born in Třinec, Czech Republic.
Pravec is a prolific discoverer of binary asteroids, expert in photometric observations and rotational lightcurves a ...
gave a diameter of 2.981 kilometers and an albedo of 0.2389.
The ''Collaborative Asteroid Lightcurve Link'' adopts the revised WISE-data and takes a diameter of 2.98 kilometers with an
absolute magnitude
Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent mag ...
of 14.8.
Rotation and shape
In 1996, 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 ...
was obtained by Czech astronomer
Petr Pravec
Petr Pravec (born September 17, 1967) is a Czech astronomer and a discoverer of minor planets, born in Třinec, Czech Republic.
Pravec is a prolific discoverer of binary asteroids, expert in photometric observations and rotational lightcurves a ...
at the
Ondřejov Observatory
The Ondřejov Observatory (; cs, Observatoř Ondřejov) is the principal observatory of the Astronomical Institute () of the Academy of Sciences of the Czech Republic. It is located near the village of Ondřejov, southeast of Prague, Czech ...
during the body's close approach to Earth within 0.1 AU. It gave a well-defined
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 hours with a brightness variation of 0.49
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 ...
().
At the same time, astronomers at the
Goldstone Observatory
The Goldstone Deep Space Communications Complex (GDSCC), commonly called the Goldstone Observatory, is a satellite ground station located in Fort Irwin in the U.S. state of California. Operated by NASA's Jet Propulsion Laboratory (JPL), its m ...
analysed ''Morpheus'' using
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 ...
delay-
Doppler imaging
Inhomogeneous structures on stellar surfaces, i.e. temperature differences, chemical composition or magnetic fields, create characteristic distortions in the spectral lines due to the Doppler effect. These distortions will move across spectral li ...
. The resultant images are not very clear, but they show that the body has a roughly triangular shape, and a 3-hour rotation period.
Seven years later, during the asteroid's next close approach in 2003, ''Morpheus'' was observed for five nights by Slovak astronomer
Adrián Galád
Adrián Galád (born 1970) is a Slovak astronomer and a discoverer of minor planets.
He is credited by the Minor Planet Center with the discovery and co-discovery of 81 numbered minor planets between 1995 and 2009, most of them in collaboratio ...
at the
Modra Observatory
The Astronomical Observatory of Modra ( sk, Astronomické observatórium Modra), also known as Modra Observatory or the Astronomical and Geophysical observatory in Modra, is an astronomical observatory located in Modra, Slovakia. It is owned and o ...
. Lightcurve analysis showed a concurring period of hours and an amplitude of 0.4 in magnitude ().
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 after
Morpheus
Morpheus ('Fashioner', derived from the grc, μορφή meaning 'form, shape') is a god associated with sleep and dreams. In Ovid's ''Metamorphoses'' he is the son of Somnus and appears in dreams in human form. From the Middle Ages, the name b ...
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 ...
. He is a god of dreams who appears in the poem ''
Metamorphoses
The ''Metamorphoses'' ( la, Metamorphōsēs, from grc, μεταμορφώσεις: "Transformations") is a Latin narrative poem from 8 CE by the Roman poet Ovid. It is considered his ''magnum opus''. The poem chronicles the history of the wo ...
'' written by the Roman poet
Ovid
Pūblius Ovidius Nāsō (; 20 March 43 BC – 17/18 AD), known in English as Ovid ( ), was a Roman poet who lived during the reign of Augustus. He was a contemporary of the older Virgil and Horace, with whom he is often ranked as one of the th ...
. He is capable to imitate any human form and to appear in dreams.
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 5 January 2015 ().
References
External links
Asteroid Lightcurve Database (LCDB) query form
)
Dictionary of Minor Planet Names Google books
– Observatoire de Genève, Raoul Behrend
*
*
*
{{DEFAULTSORT:Morpheus
004197
Discoveries by Eleanor F. Helin
Discoveries by Eugene Merle Shoemaker
Named minor planets
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