An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Math.: A symbol or number placed above and after another symbol or number (called the base) to denote the power to which the latter is to be raised. Examples: n in the expresseion aⁿ; 3 in the expression 2³.

From L. exponentem, pr.p. of exponere "put forth, explain," from → ex- "forth" + ponere "to put, to place."

Nemâ, agent noun of nemudan "to show, display," from Mid.Pers. nimūdan, from ne- "down; into;" O.Pers./Av. ni- "down; into," → ni-, + mun, Av. māy- "to measure," → display.

Of or expressed by a mathematical → exponent. → exponential curve, → exponential equation, → exponential function.

→ exponent + -ial, variant of → -al.

A curve that represents an → exponential function.

→ exponential; → curve.

An equation in which unknowns appear as exponents. Examples: 2^{3x + 1} = 32.

→ exponential; → equation.

A function in the form of y = b^x defined for every → real number x, with positive base b > 1.

→ exponential; → function.

In an exponential manner.

→ exponential; → -ly.

The exponent appearing in the power law that describes the → effective temperature of a → rotating star as a function of the → effective gravity, as deduced from the → von Zeipel theorem or law. Generalizing this law, the effective temperature is usually expressed as T_eff∝ g_eff^β, where β is the gravity darkening exponent with a value of 0.25. It has, however, been shown that the relation between the effective temperature and gravity is not exactly a power law. Moreover, the value of β = 0.25 is appropriate only in the limit of slow rotators and is smaller for fast rotating stars (Espinosa Lara & Rieutord, 2011, A&A 533, A43).

→ gravity; → darkening; → exponent.