SRc variable stars
type: Concept
broader: Semi-regular variable stars

SRa variable stars
type: Concept
broader: Semi-regular variable stars

Late-type giant stars
type: Concept
narrower: Semi-regular variable stars

SRd variable stars
type: Concept
broader: Semi-regular variable stars

Semi-regular variable stars
type: Concept
narrower: SRc variable stars
narrower: SRS variable stars
narrower: SRb variable stars
narrower: SRd variable stars
narrower: SRa variable stars
example: Betelgeuse
modified: 2022-06-24T15:27:48.646Z
modified: 2020-11-04T14:44:40.656Z
broader: Long period variable stars
broader: Late-type giant stars
alternative label: Semiregular variable stars
definition: A type of giant or supergiant pulsating variable star, with intermediate or late spectra, showing noticeable periodicity in its light changes, accompanied or sometimes interrupted by various irregularities. Periods lie in the range from 20 to more than 2000 days, while the shapes of the light curve may be rather different and variable with each cycle. The amplitudes may be from several hundredths to several magnitudes (usually 1-2 magnitudes in the V filter). Examples are Betelgeuse, Antares, and Rasalgethi. Semiregular variables are classified in several subtypes: SRA, SRB, SRC, and SRD.
contributor: AAS Frey.Katie Admin

SRS variable stars
type: Concept
broader: Semi-regular variable stars

SRb variable stars
type: Concept
broader: Semi-regular variable stars

Long period variable stars
type: Concept
narrower: Semi-regular variable stars