5535 Annefrank (), 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 suspected

contact binary In astronomy, a contact binary is a binary star system whose component stars are so close that they touch each other or have merged to share their gaseous envelopes. A binary system whose stars share an envelope may also be called an overcontac ...

from the inner asteroid belt, approximately 4.5 kilometers in diameter. It was used as a target to practice the flyby technique that the Stardust space probe would later use on the comet Wild 2. The asteroid was discovered 23 March 1942, by German astronomer

Karl Reinmuth Karl Wilhelm Reinmuth (4 April 1892 in Heidelberg – 6 May 1979 in Heidelberg) was a German astronomer and a prolific discoverer of 395 minor planets. Scientific career From 1912 to 1957, Reinmuth was working as an astronomer at the Hei ...

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 student ...

in southwest Germany. It was named after Anne Frank, a victim of the

Holocaust The Holocaust, also known as the Shoah, was the genocide of European Jews during World War II. Between 1941 and 1945, Nazi Germany and its collaborators systematically murdered some six million Jews across German-occupied Europe; ...

Orbit and classification

''Annefrank'' is a member of the Flora family, one of the largest collisional populations of stony asteroids in the main-belt. 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 ...

main-belt at a distance of 2.1–2.4 AU once every 3 years and 3 months (1,202 days). Its orbit has an eccentricity of 0.06 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 reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Ea ...

of 4 ° with respect to the ecliptic. 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

Crimea–Nauchnij The Crimean Astrophysical Observatory (CrAO, obs. code: 095) is located at Nauchnij research campus, near the Central Crimean city of Bakhchysarai, on the Crimean peninsula. CrAO is often called simply by its location and campus name, ...

in 1978, with its identification as , 36 years after its official discovery observation at Heidelberg.

Physical characteristics

''Annefrank'' has been characterized as a common

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 secon ...

Diameter, albedo and shape

On 2 November 2002, the Stardust space probe flew past ''Annefrank'' at a distance of 3079 km. Its images show the asteroid to be 6.6 × 5.0 × 3.4 km, twice as big as previously thought, and its main body shaped like a triangular prism with several visible impact craters. From the photographs, the

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 refle ...

of ''Annefrank'' was computed to be between 0.18 and 0.24. Preliminary analysis of the Stardust imagery suggests that ''Annefrank'' may be a

, although other possible explanations exist for its observed shape.

Rotation and poles

In October 2006, ground-based photometric observations were used in an attempt to measure ''Annefrank''s rotational period. Analysis of the ambiguous lightcurve gave a period of hours and a brightness variation of 0.25 magnitude with two alternative period solutions of 12 and 22.8 hours, respectively (). In January 2014, photometric observations at the Palomar Transient Factory gave a rotation period of and hours with an amplitude of 0.17 and 0.20 magnitude, respectively (). The lightcurve data suggests that ''Annefrank'' is not Lambertian, meaning that surface features, such as shadows from boulders and craters, play a role in the object's perceived brightness and not just the asteroid's relative size when seen from that orientation. The body's shortest axis is approximately aligned perpendicular to its orbital plane.

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 after Anne Frank, the Dutch-Jewish diarist who died in a

Nazi concentration camp From 1933 to 1945, Nazi Germany operated more than a thousand concentration camps, (officially) or (more commonly). The Nazi concentration camps are distinguished from other types of Nazi camps such as forced-labor camps, as well as con ...

(World War II). The official naming citation 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 T ...

on 14 May 1995 ().

References

External links

A page with images from the Stardust flyby

* ttp://www.minorplanet.info/PHP/lcdbsummaryquery.php Asteroid Lightcurve Database (LCDB) query form
info
)
Dictionary of Minor Planet Names
Google books

– Observatoire de Genève, Raoul Behrend

– Minor Planet Center * {{DEFAULTSORT:Annefrank 005535 Discoveries by Karl Wilhelm Reinmuth Named minor planets 20021102 Anne Frank 005535 19420323