What is the frequency of the Sun?
In general, the radiation from stars is composed of a wide range of frequencies. The frequency f(peak) at which a star's intensity peaks is given by
f(peak) = 59,000 x T Megahertzwhere T is the effective surface temperature of the star. The Sun's effective surface temperature is 5770 K, so the peak frequency of the Sun is f(peak) = 340 trillion hertz. To find the peak frequency of other stars, you need to know their spectral type and the relationship between spectral type and temperature.
Spectral Types can be found at:
The temperature for a given spectral class can be found at: http://ads.harvard.edu/cgi-bin/bbrowse?book=hsaa&page=68