2. In mathematics, a quantity which can have any one of a set of values or a symbol that represents such a quantity or a number which can change depending on the other numbers in an equation.
2. Characteristic of something that is able, or liable, to change suddenly and unpredictably, or likely to change often: The stock market has variable investments with profits going up and then down; often as a result of statements made by certain government agencies.
3. Descriptive of anything that is inconsistent or uneven in quality or performance; not always the same: Joan's savings account has a variable interest rate which fluctuates daily.
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2. A fuse; such as, the radio proximity fuse, set off by an electronic device incorporated within it.
A fuse that detonates a warhead when the target is within some specified region near the fuse.
Radio, radar, photoelectric, or other devices may be used as activating elements.
Contrasted with a fixed-speed turbine, which has a virtually constant rotor speed; typically a 1-2% variation.
2. A yellow super giant star that varies regularly in brightness every few days or weeks as a result of pulsations.
The time that a Cepheid variable takes to pulsate is directly related to its average brightness; the longer the period, the brighter the star.
Cepheus is a constellation of the northern hemisphere near Cassiopeia (a W-shaped constellation in the northern hemisphere near Polaris) and Draco (a large faint constellation of the northern hemisphere).
The light curve is irregular, with a varying range of brightness and of a period between peaks of brightness.
2. A star whose luminous output varies significantly with time.
Such variation may be regular; that is, eclipsing variable stars, or irregular, as with flare stars.
In addition, the variation can be intrinsic, because of changes within the star itself, or extrinsic, as the result of the interaction of one star with another.