1233 Kobresia, provisional designation , is a carbonaceous 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 central regions of the
asteroid belt, approximately 33 kilometers in diameter. It was discovered on 10 October 1931, by German astronomer
Karl Reinmuth at the
Heidelberg Observatory in southwest Germany.
The asteroid was named for the grass-like flowering plant ''
Kobresia'', a genus in the sedge family.
Orbit and classification
''Kobresia'' is a non-
family asteroid from the main belt's
background population.
It orbits the Sun in the
central
Central is an adjective usually referring to being in the center of some place or (mathematical) object.
Central may also refer to:
Directions and generalised locations
* Central Africa, a region in the centre of Africa continent, also known as ...
main-belt at a distance of 2.4–2.7
AU once every 4 years and 1 month (1,493 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 2.56 AU). Its orbit has an
eccentricity of 0.06 and an
inclination of 6
° with respect to the
ecliptic.
The body's
observation arc begins with its first observation as at Heidelberg in October 1927, or four years prior to its official discovery observation.
Physical characteristics
''Kobresia'' has been characterized as a carbonaceous
C-type asteroid by
Pan-STARRS photometric survey.
Rotation period
Two rotational
lightcurves of ''Kobresia'' were obtained by French amateur astronomer
Pierre Antonini. Lightcurve analysis of his photometric observations made in 2004 and 2006, 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 27.76 and 27.83 hours with a brightness amplitude of 0.32 and 0.34
magnitude, respectively ().
While not being a
slow rotator, ''Kobresia''s period is longer than that of the average asteroid.
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite
IRAS, the Japanese
Akari satellite and the
NEOWISE mission of NASA's
Wide-field Infrared Survey Explorer, ''Kobresia'' measures between 29.73 and 36.167 kilometers in diameter and its surface has an
albedo between 0.0305 and 0.0475.
The ''Collaborative Asteroid Lightcurve Link'' derives an albedo of 0.0396 and a diameter of 33.45 kilometers based on an
absolute magnitude of 11.5.
Naming
This
minor planet was named after a genus in the family
Cyperaceae
The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus ''Carex'' w ...
, ''
Kobresia'', a grass-like flowering plant, commonly known as "bog sedges". The author of the ''Dictionary of Minor Planet Names'' contacted Dutch astronomer
Ingrid van Houten-Groeneveld in order to confirm the meaning of this asteroid's name.
Meta-naming
The initials of the minor planets through , all discovered by Reinmuth, spell out "G. Stracke".
Gustav Stracke
Gustav, Gustaf or Gustave may refer to:
*Gustav (name), a male given name of Old Swedish origin
Art, entertainment, and media
* ''Primeval'' (film), a 2007 American horror film
* ''Gustav'' (film series), a Hungarian series of animated short cart ...
was a German astronomer and orbit computer, who had asked that no planet be named after him. In this manner Reinmuth was able to honour the man whilst honoring his wish. Nevertheless, Reinmuth directly honored Stracke by naming planet later on.
The astronomer
Brian Marsden was honored by the same type of meta-naming using consecutive initial letters in 1995, spelling out "Brian M." in the sequence of minor planets through .
Reinmuth's flowers
Due to his many discoveries,
Karl Reinmuth submitted a large list of 66 newly named asteroids in the early 1930s. The list covered his discoveries with numbers between and . This list also contained a sequence of 28 asteroids, starting with
1054 Forsytia
1054 Forsytia is a dark background asteroid, approximately 46 kilometers in diameter, from the outer regions of the asteroid belt. It was discovered on 20 November 1925, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory ...
, that were all named after plants, in particular
flowering plants ''(also see
list of minor planets named after animals and plants)''.
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:Kobresia
001233
Discoveries by Karl Wilhelm Reinmuth
Named minor planets
19311010