candela

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candela

 (cd) [kan-del´ah]
the base SI unit of luminous intensity.

can·de·la (cd),

(kan'de-lă),
The SI unit of luminous intensity, 1 lumen per m2; the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 × 1012 Hz and that has a radiant intensity in that direction of 1/683 W per steradian (solid angle).
Synonym(s): candle
[L.]

candela

The SI (International System unit) of luminous intensity in a given direction from a source emitting monochromatic radiation of a frequency of 540 X 1012 hertz, where the energy in that direction is 1.464 X 10-3/steradian.

can·de·la

(kan-dē'lă)
The SI unit of luminous intensity, 1 lumen per m2; the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 × 1012 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian (solid angle).
[L.]

candela 

The candela is the luminous intensity in a given direction of a source emitting monochromatic radiation of frequency 540 ✕ 1012 Hz and the radiant intensity of which in that direction is 1/683 watt per steradian. The candela so defined is the base unit applying to photopic quantities. Symbol: cd.
References in periodicals archive ?
For measuring the Hubble constant, though, even more distant standard candles are needed, and that's a job for supernovas.
Astronomers, however, need more than one type of standard candle. That's because no single class of star or galaxy has proved completely reliable.
Nonetheless, now that astronomers seem close to nailing down the distance to the Virgo cluster, the brightest galaxies within the cluster may, in turn, serve as standard candles in comparisons with clusters of galaxies even farther away.
This portion of the electromagnetic spectrum has numerous advantages, especially when observing Cepheid variable stars, the so-called "standard candles" that are used to determine distances to distant galaxies.
As one example, ShedRain, a manufacturer of umbrellas and raingear, has developed the WalkSafe umbrella, which uses a highly reflective material that produces reflected light equivalent to 500 standard candles. The result is an umbrella that significantly enhances the safety of pedestrians walking on dark, rainy streets.
Q I've been told standard candles are as bad for you as passive smoking because of the synthetic fragrances used.
Thank "standard candles." Measuring astronomical distances depends on certain heavenly objects, believed to shine with consistent intensity wherever they exist.
Known as standard candles, the RR Lyrae variable stars are significant in what is called the cosmic distance ladder.
If those distances are determined by standard candles, such as type la supernovae, no problem.
To create their distance ladder, Riess and colleagues combined geometrical distance measurements with "standard candles"--objects of known brightness.
My work will perform several tests of the progenitors and physics of the classical type Ia supernovae in an attempt to understand how these crucial standard candles depend on their progenitor stellar populations.
By providing a measure of the distance from Earth to remote galaxies, such Type Ia 'standard candles' underpinned the discovery of the mysterious repulsive dark energy that is driving the Universe's accelerating expansion.

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