A star is an ideograph

Ideograph

Ideograph is a term coined by rhetorical scholar and critic Michael Calvin McGee describing the use of particular words and phrases as political language in a way that captures particular ideological positions...

 whose outer edge forms a symmetrical polygon (usually rotationally so

Rotational symmetry

Generally speaking, an object with rotational symmetry is an object that looks the same after a certain amount of rotation. An object may have more than one rotational symmetry; for instance, if reflections or turning it over are not counted, the triskelion appearing on the Isle of Man's flag has...

, but if not, bilaterally

Reflection symmetry

Reflection symmetry, reflectional symmetry, line symmetry, mirror symmetry, mirror-image symmetry, or bilateral symmetry is symmetry with respect to reflection. That is, a figure which does not change upon undergoing a reflection has reflectional symmetry.In 2D there is a line of symmetry, in 3D a...

) whose vertices alternate between joining outward- and inward-pointing pairs of edges. The figure may be the border or interior of the polygon, or one or more closed polygonal paths that include all of the border and also have some legs crossing the interior. Impressions of astronomical

Astronomy

Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 stars provide the term, but specific uses may exploit the connection or not.

• In heraldry
  Heraldry
  Heraldry is the profession, study, or art of creating, granting, and blazoning arms and ruling on questions of rank or protocol, as exercised by an officer of arms. Heraldry comes from Anglo-Norman herald, from the Germanic compound harja-waldaz, "army commander"...
  
  , a mullet is a star with straight arms and typically five points.