Irregular variable: Difference between revisions

Revision as of 19:17, 29 October 2008

Revision as of 02:54, 10 April 2009

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An '''irregular variable''' is a type of [[variable star]] in which variations in brightness show no regular [[periodicity]]. There are two main sub-types of irregular variable: eruptive and pulsating.

'''Eruptive''' irregular variables are divided into three categories:

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* The third category of eruptive irregulars are the IS stars, which show rapid variations of 0.5 to 1 magnitude in a few hours or days; again, these come in subgroups ISA and ISB.

'''Pulsating''' irregular giants or supergiants, called [[slow irregular variable]]s, are all of late spectral types (K, M, C, or S), and classed as type L-LB for giants and LC for supergiants. How many of these are actually semi-regular variables that simply need more study, remains unclear.<ref>{{citation|title=Observing Variable Stars |author=Gerry Arlen Good|year= 2003|publisher=Springer Science|url= http://books.google.com/books?vid=ISBN1852334983&id=k9ViYKvKRz0C&pg=PA8&lpg=PA8&ots=AojoVu3Lpn&dq=%22Irregular+variable%22&ie=ISO-8859-1&output=html&sig=hIF3ZDs-Rh3XGKVECqONh7aKAYM|id=ISBN 18523349831-85233-498-3}}</ref>

== References ==

<references />

{{var-star-stub}}

[[Category:Irregular variables]]

{{var-star-stub}}

[[ca:Estrella variable irregular]]

[[es:Estrella variable irregular]]

[[eu:Izar aldagarri ez erregular]]

[[fr:Variable irrégulière]]

[[it:Variabile irregolare]]