Editing Semiregular variable star (section)

{{Short description|Type of variable star}}
[[File:Light curve of Betelgeuse.png|thumb|right|upright=1.5|[[Light curve]] of semiregular variable star [[Betelgeuse]]]]
In [[astronomy]], a '''semiregular variable star''', a type of [[variable star]], is a [[Red giant|giant]] or [[supergiant]] of intermediate and late (cooler) [[spectral type]]. It shows considerable periodicity in its light changes, accompanied or sometimes interrupted by various irregularities. Periods lie in the range from 20 to more than 2000 [[day]]s, while the shapes of the [[light curve]]s may be rather different and variable with each cycle.  The amplitudes may be from several hundredths to several [[Apparent magnitude|magnitudes]] (usually 1-2 magnitudes in the V filter).