1192 Prisma
1192 Prisma, provisional designation, is an elongated Phocaea asteroid from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered by German astronomer Friedrich Schwassmann at the Bergedorf Observatory in Hamburg on 17 March 1931. The asteroid was named after the Bergedorf Spectral Catalogue, an astronomical catalog.
Classification and orbit
Prisma is a member of the Phocaea family, a prominent family of S-type asteroids with their largest members being 25 Phocaea and 587 Hypsipyle. There are many Mars-crossers among this family of relatively eccentric inner main-belt asteroids.The asteroid orbits the Sun at a distance of 1.8–3.0 AU once every 3 years and 8 months. Its orbit has an eccentricity of 0.26 and an inclination of 24° with respect to the ecliptic. The body's observation arc begins at Bergedorf, one week after its official discovery observation.
Physical characteristics
Rotation, shape and pole
Photometric observations of Prisma gave a well defined rotational lightcurve with a period between 6.546 and 6.558 hours and a high brightness variation of 0.85–1.16 magnitude, which strongly indicates that the body has an elongated, non-spheroidal shape.A modeled lightcurve based on optical data from a large collaboration network also found a spin axis of in ecliptic coordinates .