4923 Clarke, provisional designation , is a stony background
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 inner regions of the
asteroid belt
The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called ...
, approximately in diameter. It was discovered on 2 March 1981, by American astronomer
Schelte Bus
Schelte John "Bobby" Bus (born 1956) is an American astronomer and discoverer of minor planets at the Institute for Astronomy (Hawaii), Institute for Astronomy of the University of Hawaii and deputy director of NASA's Infrared Telescope Facility ...
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 Australia.
The spheroidal
S-type asteroid
S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the second ...
has 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 3.14 hours.
It was named after British science fiction writer
Arthur C. Clarke
Sir Arthur Charles Clarke (16 December 191719 March 2008) was an English science-fiction writer, science writer, futurist, inventor, undersea explorer, and television series host.
He co-wrote the screenplay for the 1968 film '' 2001: A Spac ...
.
On the same night, Schelte Bus also discovered
5020 Asimov.
Orbit and classification
''Clarke'' is 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 from the main belt's
background population.
It orbits the Sun in the
inner
Interior may refer to:
Arts and media
* ''Interior'' (Degas) (also known as ''The Rape''), painting by Edgar Degas
* ''Interior'' (play), 1895 play by Belgian playwright Maurice Maeterlinck
* ''The Interior'' (novel), by Lisa See
* Interior de ...
main-belt at a distance of 1.7–2.6
AU once every 3 years and 2 months (1,147 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 2.14 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 0.20 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 7
° 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 asteroid was first observed as at
Crimea–Nauchnij
The Crimean Astrophysical Observatory (CrAO, obs. code: 095) is located at Nauchnij research campus, near the Central Crimean city of Bakhchysarai, on the Crimean peninsula. CrAO is often called simply by its location and campus name, ...
in July 1972. 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 at the Siding Spring Observatory two weeks prior to its official discovery observation on 12 February 1981.
Physical characteristics
In the
SMASS classification
An asteroid spectral type is assigned to asteroids based on their emission spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiat ...
, ''Clarke'' is a common, stony
S-type asteroid
S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the second ...
.
Rotation period
Three 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 ...
s of ''Clarke'' have been obtained from
photometric observations by the APT Observatory Group in Spain, by astronomers at the
Palomar Transient Factory
The Palomar Transient Factory (PTF, obs. code: I41), was an astronomical survey using a wide-field survey camera designed to search for optical transient and variable sources such as variable stars, supernovae, asteroids and comets. The projec ...
in California, and 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
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 R ...
().
Analysis of the best-rated lightcurve gave 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 3.143 hours with a consolidated brightness amplitude between 0.03 and 0.14
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 ...
, which indicates that the body has a nearly spheroidal, non-elongated shape ().
Diameter and albedo
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, ...
, ''Clarke'' measures between 3.367 and 3.532 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 ...
between 0.3259 and 0.366.
The ''Collaborative Asteroid Lightcurve Link'' assumes an albedo of 0.20 and calculates a diameter of 4.10 kilometers based on 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 14.3.
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 the
science fiction
Science fiction (sometimes shortened to Sci-Fi or SF) is a genre of speculative fiction which typically deals with imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, parallel unive ...
writer
Arthur C. Clarke
Sir Arthur Charles Clarke (16 December 191719 March 2008) was an English science-fiction writer, science writer, futurist, inventor, undersea explorer, and television series host.
He co-wrote the screenplay for the 1968 film '' 2001: A Spac ...
(1917–2008), author of ''
2001: A Space Odyssey''.
The official naming citation was prepared with assistance from
Richard Binzel
Richard "Rick" P. Binzel (born 1958) is an American astronomer and professor of planetary sciences at the Massachusetts Institute of Technology (MIT). He is a discoverer of minor planets, photometrist and the inventor of the Torino Scale, a metho ...
and 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 3 May 1996 (). The asteroid's name independently suggested by
Duncan Steel
Duncan I. Steel is a British space scientist. He has discoverer of minor planets, discovered several minor planets and has written four popular science books. He is a member of the International Astronomical Union, which lists him as working a ...
().
In the postscript to his novel ''
3001: The Final Odyssey'', Clarke jokingly expresses disappointment that he did not receive
asteroid 2001 as his namesake; instead, it was named for
Albert Einstein
Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory ...
.
Notes
References
External links
Asteroid Lightcurve Database (LCDB) query form
)
Dictionary of Minor Planet Names Google books
– Minor Planet Center
*
*
{{DEFAULTSORT:Clarke
004923
Discoveries by Schelte J. Bus
Named minor planets
4923 Clarke
004923
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