Discovered by L. Volta MPC designation 1191 Alfaterna Minor planet category main-belt · (outer) Inclination 18.494° Discoverer Luigi Volta Asteroid group Asteroid belt | Discovery date 11 February 1931 Alternative names 1931 CA · 1965 AA Discovered 11 February 1931 Orbits Sun Discovery site Observatory of Turin | |
Named after Nuceria Alfaterna
(ancient Roman town) Similar 193 Ambrosia, 276 Adelheid, 132 Aethra, 265 Anna, 367 Amicitia | ||
1191 Alfaterna, provisional designation 1931 CA, is a carbonaceous asteroid from the outer region of the asteroid belt, approximately 43 kilometers in diameter. It was discovered on 11 February 1931, by Italian astronomer Luigi Volta at the Observatory of Turin in northwestern Italy.
Alfaterna is a carbonaceous C-type asteroid. It orbits the Sun at a distance of 2.8–3.0 AU once every 4 years and 11 months (1,797 days). Its orbit has an eccentricity of 0.05 and an inclination of 18° with respect to the ecliptic. The first unused observation was taken at Heidelberg two nights prior to its discovery. The body's observation arc begins at Pino Torinese one week after its official discovery observation.
From 2005 to 2015, several astronomers such as Donald Pray, Henk de Groot and Raoul Behrend, Federico Manzini, as well as Laurent Bernasconi unsuccessfully tried to obtain a well-defined light-curve of Alfaterna. While Pray derived a period of 3.664 hours with an amplitude of 0.05 magnitude (U=1), the European astronomers published a tentative period of 33.12 hours (U=n.a.). As of 2017, the body's spin rate effectively remains unknown.
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, Alfaterna measures between 38.92 and 47.397 kilometers in diameter and its surface has an albedo between 0.04 and 0.0574 (without preliminary results). The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0479 and a diameter of 42.01 kilometers using an absolute magnitude of 10.8.
This minor planet is named for the ancient Roman town of "Nuceria Alfaterna", now known as Nocera Inferiore. The ancient city was founded between Pompeii and Salerno in 10th century BC. In 1957, the name was suggested by astronomer Alfonso Fresa at Turin Observatory. Naming citation was published in the Minor Planet Circulars before November 1977 (M.P.C. 2882).