1108 Demeter, provisional designation 1929 KA, is a dark asteroid from the inner regions of the asteroid belt, approximately 27 kilometers (17 miles) in diameter. It was discovered on 31 May 1929, by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory near Heidelberg, Germany.[18] The asteroid was named after Demeter, the Greek goddess of fruitful soil and agriculture.[3] It has a rotation period of 9.846 hours.
It orbits the Sun in the inner main-belt at a distance of 1.8–3.1 AU once every 3 years and 9 months (1,381 days; semi-major axis of 2.43 AU). Its orbit has an eccentricity of 0.26 and an inclination of 25° with respect to the ecliptic.[1] The asteroid was first observed at the Italian Observatory of Turin, three days prior to its official discovery observation at Heidelberg. The body's observation arc begins at Yerkes Observatory in December 1930.[18]
In June 2016, a rotational lightcurve of Demeter was obtained from photometric observations by American astronomers Tom Polakis and Brian Skiff at the Command Module Observatory (V02) in Tempe, Arizona. Lightcurve analysis gave a rotation period of 9.846 hours with an amplitude of 0.12 magnitude (U=3).[15] Observations by the Spanish OBAS group, also taken during the 2016-opposition, gave a concurring period of 9.870 hours and a brightness variation of 0.11 magnitude (U=3-).[16] The results supersede previous observations by Robert Stephens, Olivier Thizy, René Roy and Stéphane Charbonnel from July 2001, which gave a period of 9.70 and 9.701 hours with an amplitude of 0.12 and 0.14 magnitude, respectively.[13][14]
The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0464 and a diameter of 25.61 kilometers based on an absolute magnitude of 11.91.[4]
Demeter is the Greek equivalent of the Roman goddess Ceres.[3] When main-belt asteroid and dwarf planet 1 Ceres was named, the Greeks called it "Demeter" effectively translating the name into Greek, rather than using the Latin Ceres or the original Italian Cerere. However, this created a problem when asteroid Demeter was named. The Greeks resolved this by using the classical form of the name, Δημήτηρ Dēmêtēr, for the new asteroid, distinguishing it from the Modern Greek form Δήμητρα Dêmētra that had been used for 1 Ceres. This conflict did not occur in Greek-influenced Slavic languages such as Russian, which had adopted Cerera for 1 Ceres, and were thus free to use the modern Greek form Demetra for the asteroid Demeter.
