960 Birgit ( ''prov. designation'': ''or'' ) is a background asteroid, approximately in diameter, located in the Florian region of the inner asteroid belt. It was discovered on 1 October 1921, by astronomer Karl Reinmuth at the

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 southern Germany. The possibly S-type asteroid 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 8.9 hours. It was named after Birgit Asplind, daughter of Swedish astronomer

Bror Asplind Bror is a Scandinavian masculine given name which simply means 'brother'. The name has been found as early as in runestones in the form Brodhir. The name form Bror is known since the year 1536. It is also used heavily in a colloquial sense in the ci ...

(1890–1954).

Orbit and classification

Located in the Florian region, ''Birgit'' is a non- family asteroid of the main belt's background population when applying the hierarchical clustering method to its

proper orbital elements __NOTOC__ The proper orbital elements or proper elements of an orbit are constants of motion of an object in space that remain practically unchanged over an astronomically long timescale. The term is usually used to describe the three quantitie ...

. 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 ...

asteroid belt at a distance of 1.9–2.6 AU once every 3 years and 4 months (1,232 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 2.25 AU). Its orbit has an eccentricity of 0.17 and an inclination of 3 ° with respect to the ecliptic. The body's observation arc begins at Heidelberg on 25 October 1925, three weeks after its official discovery observation.

Naming

This minor planet was named after Birgit Asplind, daughter of Swedish astronomer

Bror Ansgar Asplind Bror is a Scandinavian masculine given name which simply means 'brother'. The name has been found as early as in runestones in the form Brodhir. The name form Bror is known since the year 1536. It is also used heavily in a colloquial sense in the c ...

(1890–1954). Asteroids

958 Asplinda 958 Asplinda ( ''prov. designation'': ''or'' ) is a resonant Hilda asteroid, approximately in diameter, located in the outermost region of the asteroid belt. It was discovered on 28 September 1921, by astronomer Karl Reinmuth at the Heidelberg ...

959 Arne 959 Arne ('' prov. designation:'' ''or'' ) is a background asteroid and slow rotator, approximately in diameter, located in the outer region of the asteroid belt. It was discovered by German astronomer Karl Reinmuth at the Heidelberg-Königstu ...

and

961 Gunnie 961 Gunnie ( ''prov. designation'': ''or'' ) is a very dark background asteroid from the central regions of the asteroid belt, approximately in diameter. It was discovered on 10 October 1921, by German astronomer Karl Reinmuth at the Heidelberg ...

are named after him and his other two children, respectively. The was mentioned in '' The Names of the Minor Planets'' by Paul Herget in 1955 ().

Physical characteristics

Based on its determined albedo, ''Birgit'' is an assumed S-type asteroid. The albedo determined by the Wide-field Infrared Survey Explorer (WISE) for this asteroid agrees with that assumption ''(see below)''.

Rotation period

In February 2007, a rotational lightcurve of ''Birgit'' was obtained from photometric observations by Agnieszka Kryszczyńska at Poznań Observatory, Poland, and international collaborators. Lightcurve analysis gave a

of hours with a brightness variation of magnitude (). The result supersedes observations by Federico Manzini, Roberto Crippa, and Pierre Antonini from August 2005, who determined a poorly rated period of hours with an amplitude of magnitude ().

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's WISE telescope, ''Birgit'' measures kilometers in diameter and its surface has an albedo of . Another published measurement by the WISE team gives a mean diameter of with an albedo of . The ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for a stony asteroid of 0.20 and calculates a diameter of 9.40 kilometers based on an absolute magnitude of 12.5.

Notes

References

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External links

Lightcurve Database Query
(LCDB), at ''www.minorplanet.info''
Dictionary of Minor Planet Names
Google books

– '' Geneva Observatory'', Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (1)-(5000)
– Minor Planet Center * * {{DEFAULTSORT:Birgit 000960 Discoveries by Karl Wilhelm Reinmuth Named minor planets 19211001