ASTER, a genus of composite plants (Compositae), found largely in North America, and scattered sparingly over Asia, Europe, and South America. They are usually perennial, and their flowers are arranged in numerous heads (capitula). Asters receive the name of Michaelmas and Christmas daisies, because they have heads like daisies, and, when the weather is mild, they flower up to these periods of the year. They are, consequently, valuable plants in a garden. The only British species is Aster Tripolium, found abundantly in saline marshes near the sea. One of the species (Aster alpinus) grows at a considerable height on the mountains of Europe. Some of them, such as Aster spectabilis of North America, are very showy. The plant called the Cape Aster is Agathaea amelloides, while the China aster is Callistephus chinensis. Both these plants belong also to the Natural Order Compositae. A variety of the Chinese aster, having beautifully coloured florets of rose, violet, and white, is called Reine Marguerite by gardeners.

ASTERIUS, of Cappadocia, was a heathen sophist and teacher of rhetoric in Galatia. About the year 300 he was converted to Christianity, and became the disciple of Lucian, the founder of the school of Antioch. During the persecution in 304 he relapsed into Paganism, but was received again into the church by Lucian. He is best known as an able defender of the Arian doctrine, and was styled by Athanasius the “advocate” of the Arians. His chief work was the Syntagma, but he wrote many others, chiefly commentaries. Cf. Mountfaucon, Collectio Nova PP. et Script. Groec.

ASTERIUS, Bishop of Amasia, in Pontus, in the end of the 4th and in the beginning of the 5th century. His fame rests chiefly on his Homilies, which were greatly esteemed in the Eastern Church. Most of these have been lost, but five were published in a 4to vol. by Ph. Rubenius of Antwerp in 1615, under the title Asterii Amas. Homil. Quinque, Gr. et Lat. Combefie published six more, so that we have eleven complete; and Dupin gives fragments of at least twenty-two.

ASTEROIDS, the name given to a large number of small planets, which revolve round the sun in orbits lying between those of Mars and Jupiter. They are all extremely small, their brightness seldom exceeding that of stars of the eighth magnitude; their paths, which cross and recross each other, extend over a belt about 250,000,000 miles in breadth; and the eccentricities of the orbits of many of them, and the inclinations of their planes to the plane of the ecliptic, are much greater than those of the larger planets. All the asteroids have been discovered during the present century. The first seen, Ceres, was discovered by Piazzi at Palermo on the first day of the century (Jan. 1, 1801), Pallas was seen in 1802, Juno in 1804, and Vesta in 1807. The next, Astrøea, was not discovered till 1845; three more were seen in 1847, and since that time the number has been increased every year, amounting at the end of 1874 to 140. (See Astronomy, p. 806.)