969 Leocadia

969 Leocadia (prov. designation: or ) is a very dark background asteroid from the inner regions of the asteroid belt, approximately 19 km in diameter. It was discovered on 5 November 1921, by Russian astronomer Sergey Belyavsky at the Simeiz Observatory on the Crimean peninsula. The uncommon F-type asteroid (FX) has a rotation period of 6.9 hours and is likely regular in shape. Any reference of the asteroid's name to a person is unknown.

Orbit and classification
Leocadia is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements. It orbits the Sun in the inner main-belt at a distance of 2.0–3.0 AU once every 3 years and 10 months (1,411 days; semi-major axis of 2.46 AU). Its orbit has an eccentricity of 0.21 and an inclination of 2° with respect to the ecliptic. The body's observation arc begins at Uccle Observatory in February 1933, more than a decade after its official discovery observation Simeiz Observatory on 5 November 1921.

Naming
This minor planet is named after a Feminine Russian first name. Any reference of this name to a person or occurrence is unknown.

Unknown meaning
Among the many thousands of named minor planets, Leocadia is one of 120 asteroids, for which no official naming citation has been published. All of these low-numbered asteroids have numbers between and  and were discovered between 1876 and the 1930s, predominantly by astronomers Auguste Charlois, Johann Palisa, Max Wolf and Karl Reinmuth.

Physical characteristics
In the Tholen classification (FXU:), Leocadia is an uncommon and dark F-type asteroid, somewhat similar to that of an X-type, though with an unusual (U) and noisy spectra.

Rotation period
In December 2006, a rotational lightcurve of Leocadia was obtained from photometric observations by Italian amateur astronomers Roberto Crippa and Federico Manzini at the Sozzago Astronomical Station. Lightcurve analysis gave a rotation period of $17.321 km$ hours with a brightness amplitude of $19.37 km$ magnitude (U=2), which is indicative of a rather spherical, non-irregular shape.

Diameter and albedo
According to the surveys carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), the Japanese Akari satellite, and the Infrared Astronomical Satellite IRAS, Leocadia measures $19.51 km$, $6.87 h$ and $0.019$ kilometers in diameter, and its surface has a very low albedo of $0.044$, $0.045$ and $0.621$, respectively. Additional measurements by the WISE telescope were published giving a mean diameter as low as $0.227$. The Collaborative Asteroid Lightcurve Link adopts the result from IRAS, that is, an albedo of 0.0435 and a diameter of 19.51 kilometers based on an absolute magnitude of 9.22.

An asteroid occultation on 19 August 2013, gave a best-fit ellipse dimension of 19.0&thinsp;×&thinsp;19.0 kilometers. These timed observations are taken when the asteroid passes in front of a distant star. However the measurements for Leocadia were of poor quality.