Space and Solar Definitions - X

A range of microwave radio frequencies in the neighborhood of 8 to 12 GHz.

X-ray

Electromagnetic radiation in the neighborhood of 100 picometer wavelength.

X-Ray Background

A daily average background x-ray flux in the 1 to 8 angstrom range. It is a midday minimum designed to reduce the effects of >flares.

X-Ray Burst

A temporary enhancement of the x-ray emission of the sun. The time-intensity profile of soft x-ray bursts is similar to that of the h-alpha profile of an associated flare.

X-Ray Flare Class

Rank of a flare based on its x-ray energy output. Flares are classified by the order of magnitude of the peak burst intensity (i) measured at the earth in the 1 to 8 angstrom band as follows: class (in watt/sq. Meter) b i < 1.0e-06 c 1.0e-06 <= i <= 1.0e-05 m 1.0e-05 <= i <= 1.0e-04 x i >= 1.0e-04.