1303 Luthera, provisional designation , is a dark
asteroid
An asteroid is a minor planet of the Solar System#Inner solar system, 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 o ...
and the parent body of the
Luthera family
An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. A ...
, located in the outermost 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 ...
. It measures approximately 90 kilometers in diameter. The asteroid was discovered on 16 March 1928, by astronomer
Friedrich Schwassmann
Friedrich Karl Arnold Schwassmann (25 March 1870 – 19 January 1964) was a German astronomer and a discoverer of 22 minor planets and 4 comets, who worked at AOP in Potsdam and at Bergedorf Observatory in Hamburg.
He was co-discoverer with ...
at the
Bergedorf Observatory in Hamburg, Germany, and later named after German astronomer
Robert Luther.
Orbit and classification
''Luthera'' is the
parent body
In meteoritics, a parent body is the celestial body from which originates a meteorite or a class of meteorites.
Identification
The easiest way to correlate a meteorite with a parent body is when the parent body still exists. This is the case fo ...
of the
Luthera family
An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. A ...
(), a smaller
asteroid family
An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. A ...
of less than 200 known members.
It orbits the Sun in the
outermost asteroid belt at a distance of 2.9–3.6
AU once every 5 years and 10 months (2,120 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 lo ...
of 3.23 AU). Its orbit has an
eccentricity of 0.10 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 19
° 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 agai ...
.
The asteroid was first observed as at
Simeiz Observatory
Simeiz Observatory (also spelled Simeis or Simeïs) was an astronomy research observatory until the mid-1950s. It is located on Mount Koshka, Crimea, , by the town of Simeiz.
Part of the Crimean Astrophysical Observatory, it is currently used for ...
in May 2017. 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
Heidelberg Observatory
Heidelberg (; Palatine German: ') is a city in the German state of Baden-Württemberg, situated on the river Neckar in south-west Germany. As of the 2016 census, its population was 159,914, of which roughly a quarter consisted of students. ...
in April 1928, or one month after its official discovery observation at Bergedorf.
Physical characteristics
Due to its low
geometric albedo
In astronomy, the geometric albedo of a celestial body is the ratio of its actual brightness as seen from the light source (i.e. at zero phase angle) to that of an ''idealized'' flat, fully reflecting, diffusively scattering ( Lambertian) disk w ...
, ''Luthera'' is an assumed carbonaceous
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 ...
,
while the overall
spectral type
In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting th ...
for members of the
Luthera family
An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. A ...
is that of an
X-type.
Rotation period
In February 2008, 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 ''Luthera'' was obtained from photometric observations by Mexican astronomer
Pedro Sada at the
University of Monterrey, Mexico. Lightcurve analysis gave a short
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 5.878 hours with a low brightness variation of 0.05
magnitude, indicative for a nearly spherical shape ().
A lower-rated lightcurve with a period of 7.92 hours and an amplitude of 0.06 magnitude was obtained by French amateur astronomer
Pierre Antonini in May 2009 ().
Diameter and albedo
According to the surveys carried out by the Japanese
Akari satellite and 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 20 ...
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 2 ...
, ''Luthera'' measures between 81.685 and 112.74 kilometers in diameter and its surface has a low
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 ...
between 0.024 and 0.059.
The ''Collaborative Asteroid Lightcurve Link'' derives an albedo of 0.0387 and a diameter of 85.08 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 we ...
of 9.5.
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 '' ...
was named after German astronomer
Karl Theodor Robert Luther (1822–1900), who was a
discoverer of minor planets himself, most notably
17 Thetis,
90 Antiope (
binary) and
288 Glauke (
slow rotator). The official naming citation was mentioned in ''
The Names of the Minor Planets
Paul Herget (January 30, 1908 – August 27, 1981) was an American astronomer and director of the Cincinnati Observatory, who established the Minor Planet Center after World War II.
Career
Herget taught astronomy at the University of Cincinn ...
'' by
Paul Herget in 1955 (). The lunar crater ''
Luther'' has also been named after him.
References
External links
Asteroid Lightcurve Database (LCDB) query form
)
Dictionary of Minor Planet Names Google books
– Observatoire de Genève, Raoul Behrend
– Minor Planet Center
*
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{{DEFAULTSORT:Luthera
001303
Discoveries by Friedrich Karl Arnold Schwassmann
Named minor planets
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