1663 van den Bos, 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. ...

and an exceptionally slow rotator from the inner regions of the asteroid belt, approximately 12 kilometers in diameter. It was discovered on 4 August 1926, by English astronomer

Harry Edwin Wood Harry Edwin Wood (3 February 1881 – 27 February 1946) was an English astronomer, director of the Union Observatory in Johannesburg, and discoverer of minor planets. Wood was born in Manchester, graduating from Manchester University in 1902 w ...

at Johannesburg Observatory in South Africa. It was later named after astronomer

Willem Hendrik van den Bos Willem Hendrik van den Bos (25 September 1896 – 30 March 1974) was a Dutch astronomer who worked at the Union Observatory in South Africa and became its director in 1941. He discovered nearly new double stars, made more than astronomical me ...

Orbit and classification

The

S-type asteroid S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the second ...

is a member of the Flora family, a large group of stony asteroids in the main-belt. It orbits the Sun at a distance of 1.8–2.6 AU once every 3 years and 4 months (1,224 days). Its orbit has an eccentricity of 0.18 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 5 ° with respect to the ecliptic. In March 2082, ''van den Bos'' will pass 29 Amphitrite at a distance of . 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 with a post-recovery observation taken at Johannesburg in 1936, when it was also identified as , which is a full decade after its official discovery observation from 1926.

Physical characteristics

Slow rotator

In October 2010, a rotational lightcurve of ''van den Bos'' was obtained from photometric observations by astronomers

Robert Stephens Sir Robert Graham Stephens (14 July 193112 November 1995) was a leading English actor in the early years of Britain's Royal National Theatre. He was one of the most respected actors of his generation and was at one time regarded as the natur ...

and David Higgins. It 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 740 hours with a brightness variation of 0.80 magnitude (). It is one of the slowest rotating minor planets ''(see list)'' and a suspected tumbler, that has a non-principal axis rotation. At the same time, photometric observations at the Shadowbox Observatory gave an alternative, yet ambiguous period of 155 hours with an amplitude of 0.5 magnitude ().

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite and 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, ...

with its subsequent NEOWISE mission, ''van den Bos'' measures between 7.58 and 13.54 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 ...

between 0.171 and 0.255. The ''Collaborative Asteroid Lightcurve Link'' derives an albedo of 0.2045 and a diameter of 12.25 kilometers using an absolute magnitude of 11.9.

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 in honor of Dutch-born, South African astronomer

(1896–1974), former director of the Union Observatory (1941–1956) and president of the ''Astronomical Society of South Africa'' (1943–1955). He made visual micrometric observations and discovered thousands of

double star In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes. This occurs because the pair either forms a binary star (i.e. a bi ...

s. 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 1 July 1972 ().

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:van den Bos 001663 Discoveries by Harry Edwin Wood Named minor planets 001663 19260804