2004 Lexell, provisional designation , is a stony Florian
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 7.5 kilometers in diameter. The asteroid was discovered on 22 September 1973, by Soviet astronomer
Nikolai Chernykh
Nikolai Stepanovich Chernykh (russian: Никола́й Степа́нович Черны́х) (6 October 1931 – 25 May 2004Казакова, Р.К. Памяти Николая Степановича Черных'. Труды Государст ...
at the
Crimean Astrophysical Observatory
The Crimean Astrophysical Observatory (CrAO, List of observatory codes, obs. code: IAU code#095, 095) is located at Nauchnij research campus, near the Central Crimean city of Bakhchysarai, on the Crimean peninsula. CrAO is often called ...
in Nauchnij, on the Crimean peninsula, and later named for Swedish-Russian astronomer and mathematician
Anders Johan Lexell
Anders Johan Lexell (24 December 1740 – ) was a Finnish-Swedish astronomer, mathematician, and physicist who spent most of his life in Imperial Russia, where he was known as Andrei Ivanovich Leksel (Андрей Иванович Лексе ...
.
Classification and orbit
''Lexell'' is a member of the
Flora family
The Flora family (''adj. Florian''; ; also known as ''Ariadne family'') is a prominent family of stony asteroids located in the inner region of the asteroid belt. It is one of the largest families with more than 13,000 known members, or approx ...
, one of the largest collisional populations of
stony asteroids. It orbits the Sun at a distance of 2.0–2.3
AU once every 3 years and 2 months (1,169 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 0.08 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 2
° 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 identified as at the Finnish
Turku Observatory
Turku ( ; ; sv, Åbo, ) is a city and former capital on the southwest coast of Finland at the mouth of the Aura River, in the region of Finland Proper (''Varsinais-Suomi'') and the former Turku and Pori Province (''Turun ja Porin lääni''; ...
in November 1938, 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 35 years prior to its official discovery observation at Nauchnij.
Physical characteristics
Pan-STARRS
The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1; List of observatory codes, obs. code: IAU code#F51, F51 and Pan-STARRS2 obs. code: IAU code#F52, F52) located at Haleakala Observatory, Hawaii, US, consists of astronomical c ...
photometric survey characterized ''Lexell'' as a LS-type asteroid, which transitions between the common
S-type and rare
L-type asteroid
L-type asteroids are relatively uncommon asteroids with a strongly reddish spectrum shortwards of 0.75 μm, and a featureless flat spectrum longwards of this. In comparison with the K-type, they exhibit a more reddish spectrum at visible wavele ...
.
Rotation period
In March 2013, two 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 ''Lexell'' were obtained from photometric observations by Gary Haagen at Stonegate Observatory, Massachusetts, and by a group of astronomers at the Oakley Southern Sky Observatory (), Australia. Lightcurve analysis 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 5.441 and 5.4429 hours with a brightness variation of 0.45 and 0.42
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 ...
, respectively ().
In February 2013, observations made by French amateur astronomer
Pierre Antonini
Pierre Antonini is a retired French mathematics professor and amateur astronomer who has discovered several minor planets and two supernovae at his private Observatoire de Bédoin (Bedoin Observatory; observatory code: 132) located at Bédoi ...
gave a concurring period of 5.44 hours with an amplitude of 0.51 magnitude ().
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, ...
, ''Lexell'' measures 7.255 and 7.456 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 0.306 and 0.2908, respectively.
The ''Collaborative Asteroid Lightcurve Link'' assumes an albedo of 0.24 – derived from
8 Flora
Flora (minor planet designation: 8 Flora) is a large, bright main-belt asteroid. It is the innermost ''large'' asteroid: no asteroid closer to the Sun has a diameter above 25 kilometres (20% that of Flora), and not until 20-km 149 Medusa was dis ...
, the largest member and namesake of the Flora family – and calculates a diameter of 7.82 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 12.7.
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
Anders Johan Lexell
Anders Johan Lexell (24 December 1740 – ) was a Finnish-Swedish astronomer, mathematician, and physicist who spent most of his life in Imperial Russia, where he was known as Andrei Ivanovich Leksel (Андрей Иванович Лексе ...
(1740–1784), a Swedish-Russian astronomer and mathematician. The official 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 15 October 1977 ().
The lunar crater ''
Lexell'' was also named in his honor, as is
Lexell's Comet
D/1770 L1, popularly known as Lexell's Comet after its orbit computer Anders Johan Lexell, was a comet discovered by astronomer Charles Messier in June 1770.Other comets named after their orbit computer, rather than discoverer, are 27P/Cromme ...
, of which he computed its orbit.
References
External links
Asteroid Lightcurve Database (LCDB) query form
)
Dictionary of Minor Planet Names Google books
– Observatoire de Genève, Raoul Behrend
– Minor Planet Center
*
*
{{DEFAULTSORT:Lexell
002004
Discoveries by Nikolai Chernykh
Named minor planets
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