1760 Sandra

1760 Sandra, provisional designation, is a carbonaceous asteroid from the outer regions of the asteroid belt, approximately 35 kilometers in diameter. It was discovered on 10 April 1950, by South African astronomer Ernest Johnson at Union Observatory in Johannesburg, and named after his granddaughter Sandra.

Orbit and classification
Sandra is a carbonaceous C-type asteroid that orbits the Sun in the outer main-belt at a distance of 2.7–3.6 AU once every 5 years and 7 months (2,041 days). Its orbit has an eccentricity of 0.13 and an inclination of 8° with respect to the ecliptic. It was first identified as at the discovering observatory. The body's observation arc begins with its identification as at Heidelberg in 1935, or 15 years prior to its official discovery observation at Johannesburg.

Lightcurve
In April 2006, a rotational lightcurve of Sandra was obtained from photometric observations by French amateur astronomer Pierre Antonini. Lightcurve analysis gave a well-defined rotation period of 6.5668 hours with a brightness variation of 0.42 magnitude (U=3).

Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Sandra measures between 33.989 and 37.71 kilometers in diameter and its surface has an albedo between 0.034 and 0.054. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0542 and a diameter of 36.03 kilometers with on an absolute magnitude of 11.0.

Naming
This minor planet was named by the South African discover Ernest Johnson after his granddaughter Sandra. The official was published by the Minor Planet Center on 20 February 1976 (M.P.C. 3934).