Definitions

# proper motion

Apparent motion of a star across the celestial sphere at right angles to the observer's line of sight, generally measured in seconds of arc per year. Any radial motion (toward or away from the observer) is not included. Edmond Halley was the first to detect proper motions; the largest known is that of Barnard's star, about 10 seconds yearly.

Proper may refer to:

• Proper (liturgy), the part of a Christian liturgy that is specific to the date within the Liturgical Year
• Proper frame, such system of reference in which object is stationary (non moving), sometimes also called a co-moving frame
• Proper, in heraldry, means depicted in natural colors
• Proper or appropriate conduct

In mathematics:

• Proper map, in topology , a property of continuous function between topological spaces, if inverse images of compact subsets are compact
• Proper morphism, in algebraic geometry, an analogue of a proper map for algebraic varieties
• Proper transfer function, a transfer function in control theory in which the degree of the numerator does not exceed the degree of the denominator
• Proper subset
• Proper space
• It is also used to indicate a subspace or a subset is strictly smaller than its parent—see "strict"