What is the meaning of Asterism?

An unofficial constellation (small group of stars that forms a visible pattern).

A rarely used typographical symbol of three asterisks arranged in a triangle, , used to call attention to a passage or to separate subchapters in a book. Distinct from a dinkus which also uses asterisks to separate.

A star-shaped figure exhibited by some crystals by reflected light (as in a star sapphire) or by transmitted light (as in some mica).

asterism

Source: wiktionary.org