What is "anthelion"

Parhelion \Par*hel"ion\, n.; pl. Parhelia. [L. parelion, Gr. ?, ?; para` beside + ? the sun.] A mock sun appearing in the form of a bright light, sometimes near the sun, and tinged with colors like the rainbow, and sometimes opposite to the sun. The latter is usually called an anthelion. Often several mock suns appear at the same time. Cf. Paraselene.

n. A faint, white halo rarely seen in the sky opposite the sun on the parhelic circle

An anthelion (plural anthelia, from late Greek ανθηλιος, "opposite the sun") is a rare optical phenomenon appearing on the parhelic circle opposite to the sun as a faint white halo, not unlike a sundog.

How anthelions are formed is disputed. Walter Tape, among others, has argued they are not separate haloes, but simply where various haloes caused by horizontally oriented column-shaped ice crystals coincide on the parhelic circle to create a bright spot. If this theory is correct, anthelia should only appear together with these other haloes.

However, anthelia occur unaccompanied by other plate crystal haloes, thus scientists have produced alternative explanations. The Dutch professor S.W. Visser proposed they form by two exterior light reflections in quadrangular prisms, while Robert Greenler has suggested two interior reflection in column-shaped crystals produces the phenomenon.

While the anthelion area is usually sparse on haloes, in a complex display it features various rare optic phenomena: Flanking the anthelion on the parhelic circle are two 120° parhelia (and two Liljequist parhelia) caused by plate crystals. The Tricker and diffuse arcs are produced in singly oriented column crystals and form an Ankh-like shape passing through the anthelion. Wegener arcs occasionally crosses the sky to converge in the anthelion.

Anthelion are a Taiwanese symphonic black metal band. The current members are Code, Zeist, Troy and Siniz.