1309 Hyperborea 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 outermost regions of the asteroid belt, approximately 57 kilometers in diameter. It was discovered on 11 October 1931, by Soviet astronomer Grigory Neujmin at the Simeiz Observatory on the Crimean peninsula, and given the provisional designation . The asteroid was named after Hyperborea, the northern homeland of a Greek mythical race of giants.

Orbit and classification

''Hyperborea'' is a non- family asteroid of the main belt's background population. It orbits the Sun in the outermost asteroid belt at a distance of 2.7–3.7 AU once every 5 years and 9 months (2,098 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 3.21 AU). Its orbit has an eccentricity of 0.15 and an inclination of 10 ° with respect to the ecliptic. The body's observation arc 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. ...

with its first observations as in September 1919, or 12 years prior to its official discovery observation at Simeiz.

Physical characteristics

''Hyperborea'' has been characterized as a carbonaceous C-type asteroid by Pan-STARRS photometric survey.

Rotation period

Between 2002 and 2017, four rotational lightcurves of ''Hyperborea'' were obtained from photometric observations by astronomers Francisco Sold and Pierre Antonini, as well as by astronomers at the Oakley Southern Sky and

Rozhen Observatory Rozhen Observatory ( bg, Национална астрономическа обсерватория - Рожен, ''НАО-Рожен''; en, National Astronomical Observatory - Rozhen, ''NAO-Rozhen''), also known as the Bulgarian National Astron ...

in Australia and Bulgaria, respectively (). The consolidated 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 13.88 hours with a brightness amplitude between 0.34 and 0.41 magnitude.

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, ''Hyperborea'' measures between 55.14 and 64.40 kilometers in diameter and its surface has an albedo between 0.03 and 0.0450. The ''Collaborative Asteroid Lightcurve Link'' derives an albedo of 0.0411 and a diameter of 57.11 kilometers based on an absolute magnitude of 10.3.

Naming

This minor planet was named after Hyperborea, the homeland of the Hyperboreans, a Greek mythical race of giants associated with the cult of Apollo. Herodotus placed the region far to the north of Thrace beyond the North Wind. It was therefore believed to be a region of perpetual sunshine.

Lutz Schmadel Lutz Dieter Schmadel (2 July 1942, in Berlin – 21 October 2016) was a German astronomer and a prolific discoverer of asteroids, who worked at the Astronomisches Rechen-Institut (ARI) of the University of Heidelberg. His special interest was t ...

, the author of the ''Dictionary of Minor Planets'', learned about the naming from Russian astronomer Nataliya Sergeevna Samoilova-Yakhontova ''(see )''.

Orbit and classification

Physical characteristics

Rotation period

Diameter and albedo

Naming

References

External links