5535 Annefrank

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Animation of Stardust Template:'s trajectory from 7 February 1999 to 7 April 2011
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5535 Annefrank (Template:IPAc-en Template:Respell), provisional designation Template:Mp, is a stony Florian asteroid and suspected contact binary 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.<ref name="Duxbury-2004" />

The asteroid was discovered 23 March 1942, by German astronomer Karl Reinmuth at Heidelberg Observatory in southwest Germany.<ref name="MPC-Annefrank" /> It was named after Anne Frank, a victim of the Holocaust.<ref name="springer" />

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 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 of 4° with respect to the ecliptic.<ref name="jpldata" />

The body's observation arc begins at Crimea–Nauchnij in 1978, with its identification as Template:Mp, 36 years after its official discovery observation at Heidelberg.<ref name="MPC-Annefrank" />

Physical characteristics

Annefrank has been characterized as a common S-type asteroid.<ref name="lcdb" /><ref name="Duxbury-2004" />

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.<ref name="Duxbury-2004" /> From the photographs, the albedo of Annefrank was computed to be between 0.18 and 0.24.<ref name="Duxbury-2004" /> Preliminary analysis of the Stardust imagery suggests that Annefrank may be a contact binary, although other possible explanations exist for its observed shape.<ref name="Duxbury-2004" />

Rotation and poles

In October 2006, ground-based photometric observations were used in an attempt to measure AnnefrankTemplate:'s rotational period. Analysis of the ambiguous lightcurve gave a period of Template:Val hours and a brightness variation of 0.25 magnitude with two alternative period solutions of 12 and 22.8 hours, respectively (Template:Small).<ref name="lcdb" /><ref name="Schmidt-2007" />

In January 2014, photometric observations at the Palomar Transient Factory gave a rotation period of Template:Val and Template:Val hours with an amplitude of 0.17 and 0.20 magnitude, respectively (Template:Small).<ref name="Waszczak-2015" /><ref name="Chang-2015" />

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.<ref name="Schmidt-2007" />

The body's shortest axis is approximately aligned perpendicular to its orbital plane.<ref name="Duxbury-2004" />

Naming

This minor planet was named after Anne Frank, the German-Dutch-Jewish diarist who died in a Nazi concentration camp during the Second World War.<ref name="springer" /> The official naming citation was published by the Minor Planet Center on 14 May 1995 (Template:Small).<ref name="MPC-Circulars-Archive" />

External links

• A page with images from the Stardust flyby Template:Webarchive
• Ted Stryk's Stardust page, including enhanced images of 5535 Annefrank
• Asteroid Lightcurve Database (LCDB), query form (info Template:Webarchive)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (5001)-(10000) – Minor Planet Center
• Template:JPL Small Body