What is "standard candle"

Standard \Stand"ard\, a.

1. Being, affording, or according with, a standard for comparison and judgment; as, standard time; standard weights and measures; a standard authority as to nautical terms; standard gold or silver.

2. Hence: Having a recognized and permanent value; as, standard works in history; standard authors.

3. (Hort.)

   1. Not supported by, or fastened to, a wall; as, standard fruit trees.

   2. Not of the dwarf kind; as, a standard pear tree.

      Standard candle, Standard gauge. See under Candle, and Gauge.

      Standard solution. (Chem.) See Standardized solution, under Solution.

Candle \Can"dle\, n. [OE. candel, candel, AS, candel, fr. L. candela a (white) light made of wax or tallow, fr. cand["e]re to be white. See Candid, and cf. Chandler, Cannel, Kindle.]

1. A slender, cylindrical body of tallow, containing a wick composed of loosely twisted linen of cotton threads, and used to furnish light.

   How far that little candle throws his beams! So shines a good deed in a naughty world.
   --Shak.

   Note: Candles are usually made by repeatedly dipping the wicks in the melted tallow, etc. (``dipped candles''), or by casting or running in a mold.

2. That which gives light; a luminary.

   By these blessed candles of the night.
   --Shak.

   Candle nut, the fruit of a euphorbiaceous shrub ( Aleurites triloba), a native of some of the Pacific islands; -- socalled because, when dry, it will burn with a bright flame, and is used by the natives as a candle. The oil has many uses.

   Candle power (Photom.), illuminating power, as of a lamp, or gas flame, reckoned in terms of the light of a standard candle.

   Electric candle, A modification of the electric arc lamp, in which the carbon rods, instead of being placed end to end, are arranged side by side, and at a distance suitable for the formation of the arc at the tip; -- called also, from the name of the inventor, Jablockoff candle.

   Excommunication by inch of candle, a form of excommunication in which the offender is allowed time to repent only while a candle burns.

   Not worth the candle, not worth the cost or trouble.

   Rush candle, a candle made of the pith of certain rushes, peeled except on one side, and dipped in grease.

   Sale by inch of candle, an auction in which persons are allowed to bid only till a small piece of candle burns out.

   Standard candle (Photom.), a special form of candle employed as a standard in photometric measurements; usually, a candle of spermaceti so constructed as to burn at the rate of 120 grains, or 7.8 grams, per hour.

   To curse by bell, book and candle. See under Bell.

n. (context astronomy English) Any astronomical object of known absolute magnitude. Its distance can then be calculated from its apparent magnitude.

n. the basic unit of luminous intensity adopted under the Systeme International d'Unites; equal to 1/60 of the luminous intensity per square centimeter of a black body radiating at the temperature of 2,046 degrees Kelvin [syn: candle, candela, cd]