Astrophysics (index)about

U

(photometric filter for ultraviolet light)

U stands for the ultraviolet passband, or a filter implementing that passband. It is one of the passbands/filters of the UBV photometric system, in which it is centered around wavelength 365 nm, with a width of 66 nm (full width at half maximum).

The letter is also used to indicate the magnitude of the signal observed through the filter, e.g., citing "u = 1.5".


(EMR,ultraviolet,band,photometry)
http://en.wikipedia.org/wiki/Photometric_system
WaveLFreqPhoton
Energy
  
365nm821THz3.4eVU

Referenced by:
color-color diagram
color index
passband
SkyMapper Southern Survey (SMSS)
UBV photometric system
Vega

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